View Full Version : Hypothetical: What Still Needs Fixing?
Dionysusigma
04-26-15, 15:19
The AR design, is (more or less) 60 years old (http://en.wikipedia.org/wiki/AR-10#History_and_development). Since its initial development, it's been frequently and sometimes nonsensically modified, updated, made from almost every possible material, accessorized, accurized, shortened, chambered in as many different calibers as any hunting rifle line, used in every operational environment this planet has to offer, and is still going strong.
Over that time, included in numerous issues that have been addressed are a standard of gas port size requirements; buffer weight; charging handle (from the original "trigger inside the carry handle" to the comparatively-new AXTS); barrel lining, barrel profile, and total barrel composition; trigger/hammer/disconnector/spring group; sights; ergonomics (i.e. furniture options); and countless others. And all have been, more than with any other system ever in such widespread use, cross-compatible with nearly every variant produced. A person could put a BCM GFH Mod 5 charging handle on a Colt 601 (however blasphemous it might seem).
But what, in your opinion, still needs fixing? What glaring (or mildly annoying) issue bothers you? How could it be changed?
To simplify discussion, let's try to limit the possibilities within the following:
- STANAG magazine compatibility
- Mechanically safe (e.g. no paper-thin chamber walls or skeletonized uppers)
- Remain within the "small arms" definition (nothing crew-served, portable and usable by one person)
- Be fully compatible with the majority of another AR - several push this envelope, from the fully ambidextrous lower of the SR15E3 to super-short PDW systems, but may be included because they can still be "mated" with the other half of the system
- Use materials that currently exist (no Star Wars Durasteel bolts or using antimatter instead of H335!)
Edited to add: This is all made from the assumption that the AR operating system (for lack of a better descriptor) is the pinnacle of firearms development. For the sake of argument, let's maintain that bias. The Sig MCX thread (https://www.m4carbine.net/showthread.php?165246-SIG-MCX-When-is-an-AR-not-an-AR) comes to mind...
Personally, I think they have been ruining it since 1980.
They started with a rifle that worked, and weighted a tad over 6-1/3 lbs unloaded, and a tad over 7.3 lbs with a full magazine and sling.
But, now they have a carbine that has 5.5 inches less barrel, shoots bullets 300 fps slower and now weighs slightly more, burns through bolts in 5000 rounds, and isn't quite as reliable as the M16A1*. The M16A4 weighs the same as an unloaded M14....
* In 1968 the US Army testing reported a Mean Time Between Stoppages at around 4200 to 4500 rounds (http://www.dtic.mil/docs/citations/ADA953116), the M4 has about 3600 MRBS (https://peosoldier.army.mil/docs/WeaponsReliabilityInformationPaper-Oct%2009.pdf)
http://www.dtic.mil/docs/citations/ADA953116[/url]), the M4 has about 3600 MRBS (https://peosoldier.army.mil/docs/WeaponsReliabilityInformationPaper-Oct%2009.pdf)
I'd be interesting in how today's mid-length gas system offerings compare with current mags (e.g. Magpul M3) and properly lubed(e.g. VTAC Rand CLP).
BufordTJustice
04-26-15, 20:54
With the implementation of the grossly over pressure M855A1 round, a 16" barrel with Noveske-length intermediate gas system, a carrier with delayed unlocking and pressure reduction features, Vltor A5 system, an improved bolt, a free float rail system using a new standard such as keymod or Mlok, and a barrel contour similar to a heavy ELW (continuous taper) would all be common sense, COTS solutions which could be implemented very quickly and at relatively little cost compared to something like, say, THE F-35 LIGHTNING II. [emoji12]
mkmckinley
04-26-15, 21:06
I'd like to see a standardized interface for mounting a rail/hand guard to the upper receiver completely independent of the barrel nut. Something like Larue's system or Aero's Enhanced uppers where the barrel nut only does one thing, hold the barrel down and there's a completely separate attachment method for attaching the handguard to the upper. Standardization would be in line with the AR's inherent modularity and make it easier/cheaper/better for manufacturers to design hand guards without having the reinvent the wheel. Such a system would ideally have excellent return to zero in the handguard is removed e.g. some type of self centering system or even a pin. Ideally there would be redundancies or keeper in the actual mounting hardware so like one or two screws could come loose one night and you wouldn't lose zero on your IR laser.
Standardized ambi controls including a way to lock bolt open without removing firing grip.
I'd like the charging handle redesigned to a SCAR style but retain the non-reciprocating/ self enclosed feature.
Make it impossible for a primer to stop up the trigger mechanism.
Standardized, simple, self cleaning adjustable gas regulator with stepped settings like high, medium, low.
This may be a bad idea in practice but if it could be done reliably and without adding noticeable weight then single on board battery in the pistol grip to power multiple gadgets would make the whole package streamlined.
vicious_cb
04-26-15, 21:38
All the upgrades in the world won't make a difference if your average soldier isn't taught how to properly lube and do preventive maintenance on his service weapon.
I'd like to see four particular improvements-
- Easier way to lock the bolt back without a mag
- The charging handle moved to a more convenient location
- A lightweight adjustable buttstock with a cheek piece like that used on the UBR
- The death of metal handguards
I'd like to see a standardized interface for mounting a rail/hand guard to the upper receiver completely independent of the barrel nut. Something like Larue's system or Aero's Enhanced uppers where the barrel nut only does one thing, hold the barrel down and there's a completely separate attachment method for attaching the handguard to the upper. Standardization would be in line with the AR's inherent modularity and make it easier/cheaper/better for manufacturers to design hand guards without having the reinvent the wheel. Such a system would ideally have excellent return to zero in the handguard is removed e.g. some type of self centering system or even a pin. Ideally there would be redundancies or keeper in the actual mounting hardware so like one or two screws could come loose one night and you wouldn't lose zero on your IR laser.
Standardized ambi controls including a way to lock bolt open without removing firing grip.
I'd like the charging handle redesigned to a SCAR style but retain the non-reciprocating/ self enclosed feature.
Make it impossible for a primer to stop up the trigger mechanism.
Standardized, simple, self cleaning adjustable gas regulator with stepped settings like high, medium, low.
This may be a bad idea in practice but if it could be done reliably and without adding noticeable weight then single on board battery in the pistol grip to power multiple gadgets would make the whole package streamlined.
"The NATO STANAG Powered Rail" coming soon to a military near you...
SomeOtherGuy
04-27-15, 09:56
The STANAG magazine / current magwell dimensions are one of the biggest remaining limitations. Something just a little bigger, like LWRC's proprietary six8 setup, would provide benefits with many cartridges including 5.56 (where you could run longer, higher-BC bullets).
The other remaining limitation is the bolt. It works, but it's a highly stressed component. Some improvements like those from ARP, LMT and KAC are all positive, but a larger bolt that isn't on a knife's edge would be better. The Faxon ARAK design seems very solid in fixing remaining weaknesses without introducing new ones, except for being proprietary.
Finally, while there are many good aftermarket triggers, even the best have rather slow lock time compared to the best bolt-gun triggers. If I'm redesigning things anyway I would look at changing to a striker setup and trying to get lock time down to 2ms or less.
sinlessorrow
04-27-15, 12:41
Personally, I think they have been ruining it since 1980.
They started with a rifle that worked, and weighted a tad over 6-1/3 lbs unloaded, and a tad over 7.3 lbs with a full magazine and sling.
But, now they have a carbine that has 5.5 inches less barrel, shoots bullets 300 fps slower and now weighs slightly more, burns through bolts in 5000 rounds, and isn't quite as reliable as the M16A1*. The M16A4 weighs the same as an unloaded M14....
* In 1968 the US Army testing reported a Mean Time Between Stoppages at around 4200 to 4500 rounds (http://www.dtic.mil/docs/citations/ADA953116), the M4 has about 3600 MRBS (https://peosoldier.army.mil/docs/WeaponsReliabilityInformationPaper-Oct%2009.pdf)
I see people say it burns through bolts in 5,000 rounds. The issue I have with that is the Maintenance Schedule calls for replacement of the bolt at 10,000 rounds.
So who's right? Random internet users or the mandatory maintenance schedule?
turnburglar
04-27-15, 13:02
I see people say it burns through bolts in 5,000 rounds. The issue I have with that is the Maintenance Schedule calls for replacement of the bolt at 10,000 rounds.
So who's right? Random internet users or the mandatory maintenance schedule?
Why can't both be right? 5-10k isn't a very large number to begin with. Some people would be replacing their bolt every year or two. That's hardly ideal.
I think the Arak bolt/barrel extension combo would be of benefit. But really why make these small changes? Why not just build a gun from the ground up that can handle the cartridge we want? The original ar15 was made for 222 rem, and now it appears 556 is pushing the limits of pressure and OAL.
Pick cartridge
Design gun.
I see people say it burns through bolts in 5,000 rounds. The issue I have with that is the Maintenance Schedule calls for replacement of the bolt at 10,000 rounds.
So who's right? Random internet users or the mandatory maintenance schedule?
Seems like both could be right? The schedule calls for replacement at 10,000 but sometimes they fail at 5,000, presumably due to the hotter loads.
When was the maintenance schedule written anyway? Could have been a long time ago.
sinlessorrow
04-27-15, 15:10
Seems like both could be right? The schedule calls for replacement at 10,000 but sometimes they fail at 5,000, presumably due to the hotter loads.
When was the maintenance schedule written anyway? Could have been a long time ago.
It's the most recent revision for the M4A1. Not sure on the exact date of the revision though.
To the OP,
There's a long list of issues that can be resolved with further development. Issues arise as the cost of development of them requires a profit to be made by their investment. The problem in doing so is in part due to modularity of the base rifle, everything snaps together like Lego parts. When you you make enough changes, the old parts no longer work with the new parts. The business is concerned about about building better "mouse traps" and "band aids" for the existing systems, because it's safer than than going into a platform that is at least initially proprietary to them and not compatible with the base gun.
An improved revision can be made without any doubt, take that as a given. No company would risk that investment right now, as "mouse traps" and "band aids" offer more profit and less risk, it's a no brainer.
Why can't both be right? 5-10k isn't a very large number to begin with. Some people would be replacing their bolt every year or two. That's hardly ideal.
I think the Arak bolt/barrel extension combo would be of benefit. But really why make these small changes? Why not just build a gun from the ground up that can handle the cartridge we want? The original ar15 was made for 222 rem, and now it appears 556 is pushing the limits of pressure and OAL.
Pick cartridge
Design gun.
The problem was the design of the case was insufficient from the get-go. The original military minimum estimate for effectiveness was a 55 grain bullet going 3300 fps at the muzzle, and required a max pressure of 50,000 psi. The .222 Remington was just a little too small to get that kind of performance, so Armalite moved the shoulder forward .017", and with selected powder loadings, 3300 fps could be reached while staying below the 50,000 psi limit. Springfield Arsenal suggested that the shoulder be moved forward another .030", so the case would be more versatile in powder choices to reach the 3300 fps speed and stay under 50,000 psi. But, Armalite did not feel like lengthening the magazine, so the longer case was quietly dropped. Then later it turned out that you actually cannot reliably get 3300 fps out of a .223 case and stay under 50,000 psi, so they bumped up the maximum allowable pressure, and then had to again when they went to the heavier bullet to keep the velocity up in the shorter barrel.
.222 Magnum (Springfield's suggested case) is more than capable of pushing a 55 grain bullet to 3300 fps with a wide range of powders and stay safety below 50,000 psi, also with the 62 grain bullet get 3200 fps and stay below the 55,000 Piezo/52,000 CUP limit of the original M193.
I'd like to see four particular improvements-
- Easier way to lock the bolt back without a mag
- The charging handle moved to a more convenient location
- A lightweight adjustable buttstock with a cheek piece like that used on the UBR
- The death of metal handguards
What's the issue with metal handguards? The newer M-LOK and KeyMod units are light and strong. Are you thinking of carbon fiber or something?
There are some very good suggestions listed so far.
Stronger bolts (reduced cam pin hole, stronger materials, etc), longer gas systems, not relying on the barrel nut to attach the handguard, etc. No argument here. Obviously a cost benefit analysis is required, but those would all definitely be beneficial in my view.
BufordTJustice
04-28-15, 10:28
The problem was the design of the case was insufficient from the get-go. The original military minimum estimate for effectiveness was a 55 grain bullet going 3300 fps at the muzzle, and required a max pressure of 50,000 psi. The .222 Remington was just a little too small to get that kind of performance, so Armalite moved the shoulder forward .017", and with selected powder loadings, 3300 fps could be reached while staying below the 50,000 psi limit. Springfield Arsenal suggested that the shoulder be moved forward another .030", so the case would be more versatile in powder choices to reach the 3300 fps speed and stay under 50,000 psi. But, Armalite did not feel like lengthening the magazine, so the longer case was quietly dropped. Then later it turned out that you actually cannot reliably get 3300 fps out of a .223 case and stay under 50,000 psi, so they bumped up the maximum allowable pressure, and then had to again when they went to the heavier bullet to keep the velocity up in the shorter barrel.
.222 Magnum (Springfield's suggested case) is more than capable of pushing a 55 grain bullet to 3300 fps with a wide range of powders and stay safety below 50,000 psi, also with the 62 grain bullet get 3200 fps and stay below the 55,000 Piezo/52,000 CUP limit of the original M193.
I'm going to assume that there isn't much room to push the case neck any further forward in the 5.56 case without increasing the OAL of the case?
A lot of the debate seems to center around "It's a 40 year old proven design, we'd be stupid to abandon all that research and development. We should continue developing the platform."
and
"It's a 40 year old design. It's time to abandon it, take the lessons learned and develop something completely new."
I'm going to assume that there isn't much room to push the case neck any further forward in the 5.56 case without increasing the OAL of the case?
If you push the neck any further forward you start to leave the cylindrical portion of the bullet and get into the ogive.
That case design has reached the limits of its capabilities.
You can't push the chamber pressure up any more, the bolt design can't handle it, and the limitations of physics prevent launching any heavier projectiles at the same or lower pressures.
IF you want any further improvements in bullet performance, you are going to have to get a new case.
...the limitations of physics prevent launching any heavier projectiles at the same or lower pressures...
Not so. Increase the length of the leade and change the powder accordingly and you'll see an increase in velocity without an increase in pressure.
Bufford, to use a longer case, you'll need to redesign the mag to accommodate the extra length to see any practical gain
Not so. Increase the length of the leade and change the powder accordingly and you'll see an increase in velocity without an increase in pressure.
Bufford, to use a longer case, you'll need to redesign the mag to accommodate the extra length to see any practical gain
How much can you increase the leade? .01"? .60"?
No, the leade can't be more than it is in the M16 chamber or you start to see a drop in accuracy and barrel life (shot out barrels have the origin of the rifling moved forward due to erosion among other things, so moving the origin forward is basically the same as pre-wearing out the barrel).
How much slower can you make the powder before you start to exceed the maximum port pressure? The powders that we have now are pushing the pressures to get the velocities we want. To put it a different way - What powders will give better performance out of this cartridge than we are getting today? None, because if there were such a powder, we'd be using it.
Unless some genius designs a powder that instantly reaches maximum pressure, holds flat at the pressure for about 250 microseconds then drops instantly to 12,000 psi and holds that for the next 300 microseconds then drops to zero, we reached the limits of this cartridge-bolt design.
Make a better bolt, you get a little bit more performance, or better bolt life, pick one.
StainlessSlide
04-29-15, 20:40
How much slower can you make the powder before you start to exceed the maximum port pressure?
What determines the maximum port pressure? Why not use a smaller gas port and a higher port pressure to make the integral of P dV in the expansion chamber equal? This would result in equal BCG/buffer energies.
BufordTJustice
04-29-15, 20:55
What determines the maximum port pressure? Why not use a smaller gas port and a higher port pressure to make the integral of P dV in the expansion chamber equal? This would result in equal BCG/buffer energies.
Equal average energy. Peak energy would still be higher.
The military specified that the leade of the 5.56 was to be longer than that of the 223 Remington in order to get more velocity while keeping pressure about the same. When the spec was set, the bullet to be used was the 55 ge FMJBT which isn't a very long bullet, or they might have specified an even longer leade. Service Rifle competitors do the same thing to allow them to load the longer 90 gr bullets with increased velocities. Roy Weatherby used the same trick to get more velocity from his line of proprietary calibers.
I don't know what the practical limit is, but the bottom line is it's proven to work
I'm happy with mine they way they are.
The military specified that the leade of the 5.56 was to be longer than that of the 223 Remington in order to get more velocity while keeping pressure about the same. When the spec was set, the bullet to be used was the 55 ge FMJBT which isn't a very long bullet, or they might have specified an even longer leade. Service Rifle competitors do the same thing to allow them to load the longer 90 gr bullets with increased velocities. Roy Weatherby used the same trick to get more velocity from his line of proprietary calibers.
I don't know what the practical limit is, but the bottom line is it's proven to work
The point you are missing, or avoiding, is that every cartridge has a point where its performance peaks and can advance no further unless you are willing to increase the chamber pressure. You cannot get .338 Lapua Magnum performance out of a .308 Winchester case, unless you jack up the chamber pressure to unacceptable levels, that's why long range sniping have adopted the former.
The 5.56mm military cartridge is at that point where if you need to have significantly higher performance, you going to need a bigger cartridge...
What determines the maximum port pressure? Why not use a smaller gas port and a higher port pressure to make the integral of P dV in the expansion chamber equal? This would result in equal BCG/buffer energies.
Equal average energy. Peak energy would still be higher.
There is another problem - mass flow.
A smaller port means less mass flow through the gas system. Since the time duration of the gas pressure is limited, there are boundaries on the amount mass that can enter the system. Further, it is the expansion of the gas that performs the work so the change in volume available is directly related to the initial density (mass and pressure). So, what you actually wind up with is higher peak loads from the higher pressure, but less actual work done due to the lower mass flow through the port.
You can move the port further toward the chamber to increase the time the port is pressurized to try and compensate for the lower mass flow, but the port pressure rises accordingly, so the port must be further restricted putting you back where you started, or the gas system need to be beefed up to handle the increased loads.
Yes you can do it, but you would have to re-design the whole gas system and all the reciprocating parts, basically, start with a clean sheet...
StainlessSlide
04-30-15, 08:13
I disagree. The integral is P dV, and I can get the same average P (averaged over V, not t) with a higher port pressure and a smaller port.
You say that "volume available is directly related to the initial density (mass and pressure)" , but dV in this case is the change in volume of the expansion chamber (the gas tube is not changing volume), and doesn't depend on the gas state at all. The gas state goes into the P factor through the equation of state.
If you want to talk about it in terms of mass flow ( which again, influences P through the equation of state), I can get any desired mass flow through the port by changing the port pressure. I can't think of a case where mass flow through an orifice wouldn't be monotonic increasing with respect to the pressure difference across the orifice.
Maybe it would help to define my variables
P - pressure of gas in the gas system (not the barrel or atmosphere), a function of time
V - volume of the gas system = volume of the expansion chamber plus volume of the gas tube, also a function of time
Aside from the gas port arguement...
If the question is just asking about the AR platform in general, I like to believe that there are enough aftermarket accessories to change anything about it the end user would like. Bolt catch redesign? BAD lever. Charging handle location? Side charger uppers (I'm honestly not sure if they make non reciprocating side chargers, but I don't doubt it.)
If we are talking about the M4 TDP, that's a whole other discussion.
The point you are missing, or avoiding, is that every cartridge has a point where its performance peaks and can advance no further unless you are willing to increase the chamber pressure
I do acknowledge that fact. That's why I said "I don't know what the practical limits are"
You cannot get .338 Lapua Magnum performance out of a .308 Winchester case, unless you jack up the chamber pressure to unacceptable levels, that's why long range sniping have adopted the former.
What about a WSM case?
http://s223.photobucket.com/user/airgunsniper/media/Mobile%20Uploads/20150410_174843.jpg.html
The 5.56mm military cartridge is at that point where if you need to have significantly higher performance, you going to need a bigger cartridge...
Do you have empirical data showing that increasing the leade of the chamber will not allow enough of a velocity increase for a 75 gr bullet loaded to an OAL that allows feeding from a magazine to achieve at least 3100 fps?
I do acknowledge that fact. That's why I said "I don't know what the practical limits are"
What about a WSM case? That's not a .308 case. The WSM has about 30% higher case capacity.
Do you have empirical data showing that increasing the leade of the chamber will not allow enough of a velocity increase for a 75 gr bullet loaded to an OAL that allows feeding from a magazine to achieve at least 3100 fps?You can increase the free bore all the way to the muzzle and get about 5000 fps, but will the accuracy hold up? If people regularly do it, it is possible, if no one bothers to do it, there are probably reasons.
The 5.56/.223 case is at, or nearly at, the limits of its performance at this pressure level. If there are requirements for increased performance, you'll need a different case or a different bolt design to handle the higher pressure.
It seems the brass case is the limiting factor on pressure.
The saami max pressure found in most common cartridges is 62k or 65k.
5.56 is already there.
The bolt design primarily affects fatigue life and the standard design usually holds up to one time kBs.
The 5.56/.223 case is at, or nearly at, the limits of its performance at this pressure level. If there are requirements for increased performance, you'll need a different case or a different bolt design to handle the higher pressure.
That's not a .308 case. The WSM has about 30% higher case capacity.
I didn't ask you about a 308 case. I asked you about a WSM case
You can increase the free bore all the way to the muzzle and get about 5000 fps, but will the accuracy hold up? If people regularly do it, it is possible, if no one bothers to do it, there are probably reasons.
One engineering problem at a time. Get the velocity first, solve for accuracy second.
Yes there are reasons why no one bothers to do it, but the actually are using longer leades to increase velocity
The 5.56/.223 case is at, or nearly at, the limits of its performance at this pressure level. If there are requirements for increased performance, you'll need a different case or a different bolt design to handle the higher pressure.
So, you do not have data
I'd like to see four particular improvements-
- Easier way to lock the bolt back without a mag
- The charging handle moved to a more convenient location
- A lightweight adjustable buttstock with a cheek piece like that used on the UBR
- The death of metal handguards
Weird, because some if not all of those issues have been remedied with good aftermarket solutions or new lower/upper designs.
And why the death of metal handguards?? Plastic melts you know...
Aside from the gas port arguement...
If the question is just asking about the AR platform in general, I like to believe that there are enough aftermarket accessories to change anything about it the end user would like. Bolt catch redesign? BAD lever. Charging handle location? Side charger uppers (I'm honestly not sure if they make non reciprocating side chargers, but I don't doubt it.)
If we are talking about the M4 TDP, that's a whole other discussion.
Agreed. I think most of the top-tier rifles from BCM, DD, LMT, etc are great designs; no need to really modify them from that. If you want a piston system, those are available too.
If we are talking about limits of the 5.56 cartridge, is 6.8 or 6.5 not good enough?? I'm no ballistics expert, but those 2 calibers make a good alternative in an AR15 platform don't they?
I didn't ask you about a 308 case. I asked you about a WSM case
Very pretty.
But like I said, you cannot get Lapua performance out of a .308
One engineering problem at a time. Get the velocity first, solve for accuracy second.
So, you do not have data
Do you have data that even indicates that a 15% increase in velocity can be achieved by just changing the freebore length? There is a lot of data out there that shows there is a measurable loss of accuracy by increasing the freebore.
Although, some people think that too much free bore will start to decrease the velocity, similar to an eroded throat...
https://thefiringline.com/forums/showthread.php?t=503402
http://forum.accurateshooter.com/index.php?topic=3771999.0
Most people are of the opinion that increasing the freebore gives better velocity not because to the drag-free jump, but the allowing the bullet to be seated further out giving more usable case volume.
(EDIT Since we have a COL limited by the magazine, we cannot use this particular advantage.)
If we are talking about limits of the 5.56 cartridge, is 6.8 or 6.5 not good enough?? I'm no ballistics expert, but those 2 calibers make a good alternative in an AR15 platform don't they?
I'd be interested in how people would feel about the lethality of the AR platform if 6.5 was the same price, as widely available, and marketed by the likes of BCM, Colt, Noveske, etc.
I'm not asking for magic, but what if 25 rounds of 6.5 were the standard, and at the price of 5.56. Would it "move the platform forward", or would any advantage be lost by the average user?
Very pretty.
But like I said, you cannot get Lapua performance out of a .308
Do you have data that even indicates that a 15% increase in velocity can be achieved by just changing the freebore length? There is a lot of data out there that shows there is a measurable loss of accuracy by increasing the freebore.
Although, some people think that too much free bore will start to decrease the velocity, similar to an eroded throat...
https://thefiringline.com/forums/showthread.php?t=503402
http://forum.accurateshooter.com/index.php?topic=3771999.0
Most people are of the opinion that increasing the freebore gives better velocity not because to the drag-free jump, but the allowing the bullet to be seated further out giving more usable case volume.
(EDIT Since we have a COL limited by the magazine, we cannot use this particular advantage.)
I don't have any hard data it can be done but there is evidence. I betcha dollars to donuts somebody has tried it and I'd like to see what their set up is and what the results were.
Too much free bore will result in lower velocities if it allows too much gas to leak past the bullet and loss of accuracy is a concern. However, the cannon of the M1 Abrams is a smooth bore- basically it's all free bore- in order to increase velocity. I don't know all the tricks they use to maintain accuracy.
A long leade allows a bullet to be seated out further to increase case capacity but that is an increase of what I would call the static capacity. The 5.56 chamber uses a longer leade to up the velocity without using a longer OAL and without upping the pressure. The extra jump increases case volume before peak pressure is reached. In other words, it acts as if a larger case is being used. I think of this as the dynamic case capacity (as I don't know what the actual term is). This is also the reason why 223 ammo produces lower pressure in 5.56 chamber than it does in a SAAMI spec 223 chamber (and why 5.56 ammo can produce dangerous pressures in a SAAMI spec 223 chamber). To get the velocity gain, more powder or a different powder must be used.
I think it's possible to increase the leade further to allow bullets of about 75-77 gr to achieve another 200 fps from a 20 inch barrel. If I had the resources to do so, I'd try it to see what happens
... However, the cannon of the M1 Abrams is a smooth bore- basically it's all free bore- in order to increase velocity. I don't know all the tricks they use to maintain accuracy....
A silicon rubber base seal to prevent leakage passed the sabot, PTFE ultra-low friction bore riders, carbon fiber sabot and a very low drag, high ballistic coefficient fin stabilized projectile. They also uses a muzzle reference system to the measure barrel droop and/or thermally induced bending, laser range finding that also measures if you are shooting uphill or down hill, wind sensor, the ammunition temperature is monitored, all of this data is fed to a ballistic computer which calculates the correct super-elevation and azimuth correction. The gunner and commander have 10X magnification in their sights. The ammunition also has some of the tightest specifications in terms of muzzle velocity around.
All that together gives the total system about 2.0 MOA error.
But, most of their super high muzzle velocity (>5,500 fps) is achieved by working at a chamber pressure of 83,000 to 96,000 psi and at the cost of a barrel life of 1500 full charge equivalent rounds. Even the "low pressure" training rounds have chamber pressures in the 70,000 psi range and has a muzzle velocity of 5600 fps with a 6-8 lb launch weight (projectile and sabot).
The rifled 105mm M68 tank gun gets 5000 fps at 75,000 psi with a 16 lb launch weight, so the lack of rifling isn't getting you much.
(EDIT: For comparison, the velocity difference between a 30-06 loaded with a 110 grain bullet and a 30-06 loaded with a 220 grain bullets is around 700 to 1000 fps with the same nominal chamber pressure.)
It should be noted that the reason tank guns use smooth bores is not because smooth bores give generally higher muzzle velocities, but because projectile terminal ballistics.
In order the penetrate great thicknesses of armor, you want a long, thin, high density projectile, in order to spin stabilize a long, thin, high density projectile, you need a really fast twist. A fast twist puts high shear stress on the engraved rifling of the projectile, so high in the case of big guns, that it will fail the material of the rotating band. This could be solved by using gain twist rifling, that way during the initial high loading, the twist is very slow. But, it is cheaper to forgo the rifling and just stick fins on the projectile.
Also, HEAT rounds do not like to be spun. It causes the flame jet to de-focus and reduces effectivity. The M456 HEAT round for the rifled 105mm M68 gun had teflon slip ring type obturating bands, so the rifling would not impart any spin to the projectile, but still seal in the rifling. And, the Shillelagh gun-launcher actually have a keyway broached down the length of the barrel to prevent the Shillelagh missile from rotating.
What happened to this thread?
Dionysusigma
05-01-15, 12:07
<redacted>
SomeOtherGuy
05-01-15, 19:13
What happened to this thread?
It got awesome. And off topic.
BufordTJustice
05-01-15, 19:43
It got awesome. And off topic.
This. :D
vicious_cb
05-02-15, 02:58
It ran its course.
The premise was basically, "after 60 years, what is the weakest link still unsolved in the AR-15 platform?"
Answer: 5.56x45mm.
Whats the point in trying to replace 5.56 when your average soldier cant take full advantage of the capabilities of the cartridge in the first place?
Whats the point in trying to replace 5.56 when your average soldier cant take full advantage of the capabilities of the cartridge in the first place?
The discussion morphed to the cartridge, the question asked was regarding the 'platform.' My thoughts for improvement go to ergonomics - ambidextrous controls, controls more friendly for use with cold-weather gear, electronic trigger/firing mechanism, standardized (hey it's big Army) tubes with built in lights, designators and BUIS, instead of the current hodgepodge and hanging equipment everywhere.
All of those things would help the soldiers take fuller advantage of the cartridge itself, by then it would be time to leap frog to a new weapons system using the improvements as a jumping off place.
There is still a lot of life left in the AR/M16/M4 platform.
Weird, because some if not all of those issues have been remedied with good aftermarket solutions or new lower/upper designs.
Those solutions aren't done well and locking back the bolt on an empty mag still sucks. It's easier on a FAL and that's awkward as well
And why the death of metal handguards?? Plastic melts you know...
As I said earlier- metal handguards are hot in the summer and cold in the winter and will burn/freeze your hands or other bits of exposed flesh respectively. That's just the rifle being exposed to the elements without shooting it.
I've yet to see any photos or hear reports of quality plastic AR handguards melting. Not that I believe it won't happen or that it's never happened, but even with the heavy shooting schedule of a carbine class there's nary a peep about it. Carbon fiber is also an option
I've yet to see any photos or hear reports of quality plastic AR handguards melting. Not that I believe it won't happen or that it's never happened, but even with the heavy shooting schedule of a carbine class there's nary a peep about it. Carbon fiber is also an option
There is that video showing an M4 being fired full auto until the handguards start to burn....but that is after 20 or so magazine dumps in less that 4 minutes.
Hardly a normal rate of fire, even in really heavy combat. Plastic handguards aren't and issue.
Those solutions aren't done well and locking back the bolt on an empty mag still sucks. It's easier on a FAL and that's awkward as well
As I said earlier- metal handguards are hot in the summer and cold in the winter and will burn/freeze your hands or other bits of exposed flesh respectively. That's just the rifle being exposed to the elements without shooting it.
I've yet to see any photos or hear reports of quality plastic AR handguards melting. Not that I believe it won't happen or that it's never happened, but even with the heavy shooting schedule of a carbine class there's nary a peep about it. Carbon fiber is also an option
The Magpul BAD lever is an easy addition to solve the issue on locking back on an empty bolt. Not "milspec" or military issue of course. Seriously though, locking the bolt back on empty is very minor. Is it really that hard???
Regarding the elements, well its called gloves. I believe most soldiers use them anyway, and in the civilian world its easy enough to pack with your gear. I always bring mine in any range or 3gun event due to my hands sweating, or for better grip of the weapon.
Yes, there was a video of Magpul handguards burning/melting after extended shooting. This is not usually a big issue, and really the handguard (whether plastic or not) is a minor thing.
Can we do something about all the little parts in the lower? Detents, springs, etc?
The Magpul BAD lever is an easy addition to solve the issue on locking back on an empty bolt. Not "milspec" or military issue of course. Seriously though, locking the bolt back on empty is very minor. Is it really that hard???
The BAD lever can interfere with the bolt locking back, is an exposed, unprotected mechanism and does nothing to address the awkward placement of the charging handle
Regarding the elements, well its called gloves. I believe most soldiers use them anyway, and in the civilian world its easy enough to pack with your gear. I always bring mine in any range or 3gun event due to my hands sweating, or for better grip of the weapon.
Gloves are good for protecting the hands. Gloves are not not a good reason to not switch to a handguard material that offer superior thermal management. Gloves thin enough to allow proper manipulation of firearm controls offer limited thermal protection.
Heat management isn't just about shots fired. It's about the environment. I can tell you from experience that it takes only five minutes for metal handguards to become brutally uncomfortable when the weather is really cold or when the sun is hot. That's why none of my rifles have metal handguards and why none of my ARs are black or green
Yes, there was a video of Magpul handguards burning/melting after extended shooting. This is not usually a big issue, and really the handguard (whether plastic or not) is a minor thing.
Then there is no reason NOT to use plastic.
This thread is about what would improve the AR. The areas I addressed are improvements I'd make
The Magpul BAD lever is an easy addition to solve the issue on locking back on an empty bolt. Not "milspec" or military issue of course. Seriously though, locking the bolt back on empty is very minor. Is it really that hard???
Regarding the elements, well its called gloves. I believe most soldiers use them anyway, and in the civilian world its easy enough to pack with your gear. I always bring mine in any range or 3gun event due to my hands sweating, or for better grip of the weapon.
Yes, there was a video of Magpul handguards burning/melting after extended shooting. This is not usually a big issue, and really the handguard (whether plastic or not) is a minor thing.
You are literally validating that these are indeed issues. The fact that you're saying, "Oh, just wear gloves" is a little off; the point of the discussion is correcting the issues themselves, not methods with which we can ignore them.
sinlessorrow
05-07-15, 18:01
I doubt polymer handguard will ever see real serious use in a Military role.
You will not see a FF handguard made of polymer either. It might be cool for the range, but now days I doubt anyone will be going back to them when compared to long free float rails.
Aluminum rails also draw heat away from the chamber and barrel nut and act as a heat sink. Polymer is an insulator. Also rail covers are an easy solution to hot or cold rails.
Dionysusigma
05-08-15, 01:32
I doubt polymer handguard will ever see real serious use in a Military role.
Um... what? :blink:
33159
Vietnam
33160
Grenada
33161
Desert Storm
That's... 26 years of "real serious use in a Military role" right there. The RAS for the SOPMOD program was developed and patented in 1998 (http://www.quarterbore.com/library/pdf_files/us05826363.pdf) (.pdf warning), and by the time Operation Enduring Freedom came around, several units still used the A2 handguards, developed in the 1980s. Much less the surplus weapons of those eras still in use by numerous NATO allies (such as the IDF, just to name one) who continue to use A1 and A2 handguards for "real serious use."
You will not see a FF handguard made of polymer either
Betcha it's on MagPul's "TO DO" list
Polymer is an insulator
Of COURSE it is- otherwise it'd be a poor choice to make handguards from
Do you think these rail covers make my rails look fat?
and feel fat and bloated
You will not see a FF handguard made of polymer either.
Polymer.
http://www.midwayusa.com/product/2367173012/pri-gen-iii-free-float-tube-handguard-quad-rail-ar-15-carbon-fiber
sinlessorrow
05-08-15, 08:17
Um... what? :blink:
33159
Vietnam
33160
Grenada
33161
Desert Storm
That's... 26 years of "real serious use in a Military role" right there. The RAS for the SOPMOD program was developed and patented in 1998 (http://www.quarterbore.com/library/pdf_files/us05826363.pdf) (.pdf warning), and by the time Operation Enduring Freedom came around, several units still used the A2 handguards, developed in the 1980s. Much less the surplus weapons of those eras still in use by numerous NATO allies (such as the IDF, just to name one) who continue to use A1 and A2 handguards for "real serious use."
I meant to say again, as in they will never see serious use again. Free float aluminum rails offer numerous benefits over polymer non Free float, heat shielded handguards.
Going back to heat shielded polymer handguards would be a downgrade. Also the IDF train with M4's with bent barrels...just saying, I wouldn't follow them on all gear choices.
sinlessorrow
05-08-15, 08:19
Betcha it's on MagPul's "TO DO" list
Of COURSE it is- otherwise it'd be a poor choice to make handguards from
and feel fat and bloated
You also ignore the fact that aluminum handguards reduce chamber temperature and increase rounds before cookoff. KevinB has mentioned before about this, and how the RIS greatly increased time before cookoffs over the double insulated polymer clamshell handguards. Why would you want to go back, when we have better rails that offer improvements and advantages.
So far it's all aluminum get hot, aluminum get cold, rail covers make me look fat.
Polymer handguards are a downgrade over what aluminum handguards offer.
sinlessorrow
05-08-15, 08:19
Polymer.
http://www.midwayusa.com/product/2367173012/pri-gen-iii-free-float-tube-handguard-quad-rail-ar-15-carbon-fiber
Carbon fiber. Helps to read the product description.
You also ignore the fact that aluminum handguards reduce chamber temperature and increase rounds before cookoff. KevinB has mentioned before about this, and how the RIS greatly increased time before cookoffs over the double insulated polymer clamshell handguards. Why would you want to go back, when we have better rails that offer improvements and advantages.
So far it's all aluminum get hot, aluminum get cold, rail covers make me look fat.
Polymer handguards are a downgrade over what aluminum handguards offer.
I don't ignore the fact that some aluminum handguards act as a heat sink. If they didn't, they wouldn't get so hot as to burn the shooter with high rates of fire. But that is cooling by radiation. Designing handguards to cool the barrel by convection air flow is better, whether they are metal or non-metallic. So a free float handguard made from polymer isn't a step backwards, it's trading the small advantage of heat radiation for thermal protection.
While we have gotten off into the weeds by focusing on polymer, the real point was replacing aluminum handguards with non-metallic handguards. Carbon fiber is a good material and dissipates heat quickly. Couple that with cooling slots designed to promote convection air flow and you've got a better handguard. Trouble is, carbon fiber is more expensive. Developing a free float handguard from polymer is a good, cost effective alternative.
Plastic covers make handguards fatter, heavier, costlier and are just another item to get knocked loose from the rifle and lost. I'd rather add rail sections that I'll use than add covers to rail sections I never will.
I've never seen combat, nor have I trained for combat except how to wear a MOP suit while changing chaff/flare canisters during a hot turn around on an A-10. But I have spent many long hours outdoors in miserable heat and bone aching cold with firearms, tools, machines and equipment, enough to know that outside of a narrow temperature range, metallic human interfaces are a Really Bad Idea and I have the calluses, scars, aches and pains to remind me of that fact every day
sinlessorrow
05-08-15, 10:34
I don't ignore the fact that some aluminum handguards act as a heat sink. If they didn't, they wouldn't get so hot as to burn the shooter with high rates of fire. But that is cooling by radiation. Designing handguards to cool the barrel by convection air flow is better, whether they are metal or non-metallic. So a free float handguard made from polymer isn't a step backwards, it's trading the small advantage of heat radiation for thermal protection.
While we have gotten off into the weeds by focusing on polymer, the real point was replacing aluminum handguards with non-metallic handguards. Carbon fiber is a good material and dissipates heat quickly. Couple that with cooling slots designed to promote convection air flow and you've got a better handguard. Trouble is, carbon fiber is more expensive. Developing a free float handguard from polymer is a good, cost effective alternative.
Plastic covers make handguards fatter, heavier, costlier and are just another item to get knocked loose from the rifle and lost. I'd rather add rail sections that I'll use than add covers to rail sections I never will.
I've never seen combat, nor have I trained for combat except how to wear a MOP suit while changing chaff/flare canisters during a hot turn around on an A-10. But I have spent many long hours outdoors in miserable heat and bone aching cold with firearms, tools, machines and equipment, enough to know that outside of a narrow temperature range, metallic human interfaces are a Really Bad Idea and I have the calluses, scars, aches and pains to remind me of that fact every day
Let me know when one of these ultimate, free floated, better ventilated and cooling polymer handguards hits the market.
It may be possible theoretically, but so far I have seen none that can do what aluminum handguards accomplish. While we're at it, let's adopt a polymer upper and lower as well. Haven't seen a capable version of,those made of polymer yet either.
Let me know when one of these ultimate, free floated, better ventilated and cooling polymer handguards hits the market.
Still stuck on the polymer? They make some really good carbon fiber free float handguards these days.
For the record, I never claimed aluminum handguards don't or can't use convection airflow
It may be possible theoretically, but so far I have seen none that can do what aluminum handguards accomplish
I've yet to see an aluminum handguard do what a non-metallic handguard can do. So what?
While we're at it, let's adopt a polymer upper and lower as well. Haven't seen a capable version of,those made of polymer yet either.
This strawman argument isn't even worth addressing.
Like it or not, aluminum isn't the best material for making rifle stocks. There's no question it's rugged enough for the job, but the reality is the only reason aluminum handguards became commonplace on the AR is because that's what the first quad rail was made from- and it wasn't even free floated. Continuing to make handguards from aluminum is because of institutional inertia, not because it's a clearly superior material
sinlessorrow
05-08-15, 16:46
Still stuck on the polymer? They make some really good carbon fiber free float handguards these days.
For the record, I never claimed aluminum handguards don't or can't use convection airflow
I've yet to see an aluminum handguard do what a non-metallic handguard can do. So what?
This strawman argument isn't even worth addressing.
Like it or not, aluminum isn't the best material for making rifle stocks. There's no question it's rugged enough for the job, but the reality is the only reason aluminum handguards became commonplace on the AR is because that's what the first quad rail was made from- and it wasn't even free floated. Continuing to make handguards from aluminum is because of institutional inertia, not because it's a clearly superior material
Somehow I find the inertia argument hard to believe when you have polymer receivers, carbon fiber rails, and new things like what BCM is doing. Which btw, I believe BCM has the right idea in rail materials.
I'm going with "institutional inertia" to explain the automatic resistance to nonmetallic handguards and the fact that the new rail-less designs are still aluminum. I'm going with institutional inertia again to explain my own resistance to polymer AR receivers- that and the fact polymer AR receivers are still fragile.
You mentioned carbon fiber rails- has someone made a carbon fiber handguard with carbon fiber top rail available yet? I believe Troy advertised they were bring one out but quietly dropped it from their website
PS- MagPul hinted once they might be working on a polymer free float handguard. If they do, I'll jump in and try one out
Carbon fiber. Helps to read the product description.
"Fiberglass", aka Fiber Reinforced Polymer (or plastic)
Helps if you know what a "polymer" is....
Fibre-reinforced plastic (FRP) (also fibre-reinforced polymer) is a composite material made of a polymer matrix reinforced with fibers. The fibers are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper or wood or asbestos have been used. The polymer is usually an epoxy, vinylester or polyester thermosetting plastic, and phenol formaldehyde resins are still in use.
More polymer rails:
http://store.lancer-systems.com/product/lch5-midlength-hg-full-top-rail/carbon_fiber_handguards
sinlessorrow
05-08-15, 19:46
I'm going with "institutional inertia" to explain the automatic resistance to nonmetallic handguards and the fact that the new rail-less designs are still aluminum. I'm going with institutional inertia again to explain my own resistance to polymer AR receivers- that and the fact polymer AR receivers are still fragile.
You mentioned carbon fiber rails- has someone made a carbon fiber handguard with carbon fiber top rail available yet? I believe Troy advertised they were bring one out but quietly dropped it from their website
PS- MagPul hinted once they might be working on a polymer free float handguard. If they do, I'll jump in and try one out
Let me know when a polymer handguard comes out that offers better cooling, decreased chamber temps, and can be free floated in a more secure manner than current metal handguards. Then I'll hop on the bandwagon.
sinlessorrow
05-08-15, 19:48
"Fiberglass", aka Fiber Reinforced Polymer (or plastic)
Helps if you know what a "polymer" is....
More polymer rails:
http://store.lancer-systems.com/product/lch5-midlength-hg-full-top-rail/carbon_fiber_handguards
According to PRI.
The PRI Gen III carbon fiber free float handguard is constructed of high strength carbon fiber with an aluminum barrel nut and collar
Sounds like carbon fiber to me.
And last I checked, carbon fiber and polymer are two different things. Pmags are not carbon fiber mags, and a carbon fiber rail is not polymer.
According to PRI.
The PRI Gen III carbon fiber free float handguard is constructed of high strength carbon fiber with an aluminum barrel nut and collar
Sounds like carbon fiber to me.
And last I checked, carbon fiber and polymer are two different things. Pmags are not carbon fiber mags, and a carbon fiber rail is not polymer.
I can't help it if you don't know what a polymer is...or what carbon-fiber material is.
A polymer is a large molecule made of a multiple repeating subunits. Stuff like polystyrene, amber, epoxy and the plethora of other "plastics" are polymers.
"Carbon-fiber" is technically known as "CARBON-FIBER REINFORCED POLYMER". This is because the there has to be a polymer matrix (usually an epoxy polymer, but it can be any polymer that has the desired properties) to hold the individual fibers in place. Without the polymer, you would have a giant "cotton ball" of carbon fibers, or at best a carbon fiber cloth.
Just for you edification, Glass Reinforced Polymer is the basically the same stuff except the reinforcing fibers are glass, and therefore not a strong.
Pmags, and other Magpul products are made from "Fiber Reinforced Polymers", If you cut one in half, you will notice there are very small fibers embedded in the plastic resin. This is what makes them stronger than just plain plastic.
sinlessorrow
05-08-15, 20:21
I can't help it if you don't know what a polymer is...or what carbon-fiber material is.
A polymer is a large molecule made of a multiple repeating subunits. Stuff like polystyrene, amber, epoxy and the plethora of other "plastics" are polymers.
"Carbon-fiber" is technically known as "CARBON-FIBER REINFORCED POLYMER". This is because the there has to be a polymer matrix (usually an epoxy polymer, but it can be any polymer that has the desired properties) to hold the individual fibers in place. Without the polymer, you would have a giant "cotton ball" of carbon fibers, or at best a carbon fiber cloth.
Just for you edification, Glass Reinforced Polymer is the basically the same stuff except the reinforcing fibers are glass, and therefore not a strong.
Pmags, and other Magpul products are made from "Fiber Reinforced Polymers", If you cut one in half, you will notice there are very small fibers embedded in the plastic resin. This is what makes them stronger than just plain plastic.
I know the difference. But carbon fiber is called carbon fiber, and you know when I said polymer handguards what I mean. Mistwolf got it so I'm sure you were smart enough to figure it out.
Yes carbon fiber uses polymer, but generally when someone says polymer they don't mean carbon fiber in regards to rifles.
I know the difference. But carbon fiber is called carbon fiber, and you know when I said polymer handguards what I mean. Mistwolf got it so I'm sure you were smart enough to figure it out.
Yes carbon fiber uses polymer, but generally when someone says polymer they don't mean carbon fiber in regards to rifles.
So, When you said:
Let me know when one of these ultimate, free floated, better ventilated and cooling polymer handguards hits the market.
You meant that there were no polymer handguards made out of the type of polymer you were thinking about, not the other types of polymers anyone else might come up with....
I can't help it if many people don't know enough about carbon fiber (reinforced polymer) to understand that it is a type of polymer. That's why I brought it up. Fiberglass, carbon-fiber plastics, fiber reinforced nylon, and many other types of commonly used "plastics" are all polymers and most are also fiber reinforced.
Lysander is right about polymers. I'm a bit embarrassed to admit I'd gotten so used to thinking of the material used to make MagPul products and Glock frames as "polymer", I'd forgotten that polymer reinforced with matting and polymer reinforced with cloth are both still polymer
Gloves are good for protecting the hands. Gloves are not not a good reason to not switch to a handguard material that offer superior thermal management. Gloves thin enough to allow proper manipulation of firearm controls offer limited thermal protection.
Heat management isn't just about shots fired. It's about the environment. I can tell you from experience that it takes only five minutes for metal handguards to become brutally uncomfortable when the weather is really cold or when the sun is hot. That's why none of my rifles have metal handguards and why none of my ARs are black or green.
Respectfully, but you are off base here.
I have 11 years of experience in arctic warfare, as well as deployments to Afghanistan (with 60 degree Celsius temps), and you wear gloves or mittens either way. If you lose function of your hands, your go non-op as a soldier.
Learning to manipulate your firearm while wearing mittens is a training issue and it most certainly is not only doable but improves your handling skills when wearing thinner gloves.
And just to be clear, I am not talking about going out to the range one day for a few hours, but keeping weapons and soldiers operational and functional over time (weeks) in the field.
In warm weather, the handguard heating up and being uncomfortable to hold is a non-issue, compared to the heat from shooting it.
In the cold, you need to wear gloves or mittens period, regardless of handguard materials - I was issued a G3 for 6 years, and it has a plastic handguard, I still needed to wear gloves or mittens. The coldest temp I have measured while in the field was -56 Celsius, including wind chill. Eff not wearing gloves.
Regardless, you need to protect your hands from activities not related to shooting, so might as well learn to shoot wearing gloves.
You are literally validating that these are indeed issues. The fact that you're saying, "Oh, just wear gloves" is a little off; the point of the discussion is correcting the issues themselves, not methods with which we can ignore them.
The fact is that you wear gloves when doing combat related activities, and not just because the handguard gets hot or cold.
Wearing gloves is not "ignoring" the issue, it is normal PPE.
Propellant. If we could make an advancement in propellant, then fouling, temperatures, and all sorts of nasty things could be decreased. Velocity could be increased, wear decreased, peak pressure decreased, etc. Get a cleaner propellant with more "pressure under the curve" and less peak, or who knows? Either way, I think ammunition (caseless) and propellant would be the largest changes possible. Everything else is incremental.
I agree with you about wearing gloves. They will not only protect your hands from the environment and battle damage but can also protect them from long term damage. I am all for wearing the proper PPE for the job. But proper PPE is not a substitute for having the proper safeguards in place on the machinery and power tools we use. That's what a rifle is- a power tool. The polymer handguard is better safeguard than the metallic handguard.
Stating that gloves are not a good justification for metallic handguards isn't the same as cackling "polymer handguards will free you from the tyranny of gloves forever- hahahahahaha!"
(Ok, that last part was a bit over the top but I've been working on project in the genre of Mad Science and a dramatic statement and maniacal laugh was inevitable. Excuse me, I need to get back to the lab and continue my work on the Defenestrator Device)
The polymer handguard is better safeguard than the metallic handguard.
Based on what metric, and which setting?
Why are the industry leaders in polymer accessories not building free float polymer AR handguards, if this issue is so serious as to pose a safety hazard to the user or the equipment?
Are there properties provided by using a metal on that specific component, that can not be replicated by using polymer? I am thinking countering recoil forces on accessories, zero retention issues, mounting rigidity, altered cook off threshold etc.
The three hottest areas on the gun are the chamber, the barrel and the gas block. The handguard will heat up through radiation, and all components lose heat through convection.
I have not fired an M16A1 (or similar), so I don't know how hot the handguard got, but the G3 handguard could get plenty hot from shooting, and it is plastic.
turnburglar
05-09-15, 13:35
Mistwolf- I definitely agree that polymer is better for the unclothed human to interact with than any metal alloy we have seen yet in FFR's. But is polymer capable of maintaining the precise attachment that is needed for things like lasers and optics? Some real end users do more than just Costa grip their rails and need a rail that will hold zero.
Dionysusigma
05-09-15, 15:01
(... I need to get back to the lab and continue my work on the Defenestrator Device)
You're developing a machine that... throws people out of windows? :blink:
So far, this is what I'm getting: Materials development and ammunition (specifically propellant chemistry).
What about the long tail of the bolt carrier, which requires the use of a long spring and receiver extension? There are a few buffer and carrier systems out there that greatly reduce this dimension, but still seem to be "relatively untested Boutique accessories." e.g. the Troy M7A1 PDW (https://troyind.com/products/pdw-stock-kit-blk) stock, MVB ARC (https://mvbindustries.com/product/arc-stock/) stock, or NEA CCS (http://www.neaginc.com/3_accessories.html) stock; and the ARES Defense SCR (http://www.aresdefense.com/?page_id=729).
BufordTJustice
05-09-15, 19:20
Propellant. If we could make an advancement in propellant, then fouling, temperatures, and all sorts of nasty things could be decreased. Velocity could be increased, wear decreased, peak pressure decreased, etc. Get a cleaner propellant with more "pressure under the curve" and less peak, or who knows? Either way, I think ammunition (caseless) and propellant would be the largest changes possible. Everything else is incremental.
Agreed. Possibly a refinement of the Hornady Superformance powder.
sinlessorrow
05-09-15, 19:47
You're developing a machine that... throws people out of windows? :blink:
So far, this is what I'm getting: Materials development and ammunition (specifically propellant chemistry).
What about the long tail of the bolt carrier, which requires the use of a long spring and receiver extension? There are a few buffer and carrier systems out there that greatly reduce this dimension, but still seem to be "relatively untested Boutique accessories." e.g. the Troy M7A1 PDW (https://troyind.com/products/pdw-stock-kit-blk) stock, MVB ARC (https://mvbindustries.com/product/arc-stock/) stock, or NEA CCS (http://www.neaginc.com/3_accessories.html) stock; and the ARES Defense SCR (http://www.aresdefense.com/?page_id=729).
K1A1 still see a plenty of use.
http://s1231.photobucket.com/user/elvisshoe/media/IMG_0023.jpg.html
K1A1 still see a plenty of use.
http://s1231.photobucket.com/user/elvisshoe/media/IMG_0023.jpg.html
If you are talking about a version of the Daewoo K1A, I would prefer a lots of others over these. What a blast from the past though, haven't even seen one these in 15+ years.
sinlessorrow
05-09-15, 20:20
If you are talking about a version of the Daewoo K1A, I would prefer a lots of others over these. What a blast from the past though, haven't even seen one these in 15+ years.
Still in use with the Korean special forces.
http://www4.pictures.zimbio.com/gi/South+Korean+Special+Forces+Participate+Winter+vBb17zfvA2Ol.jpg
Stoner driven and allows for a folding stock.
I'm not informed of what developments evolved past the the early 90's in these. At the time they were not as reliable, and had control issues when compared to other platforms.
Propellant. If we could make an advancement in propellant, then fouling, temperatures, and all sorts of nasty things could be decreased. Velocity could be increased, wear decreased, peak pressure decreased, etc. Get a cleaner propellant with more "pressure under the curve" and less peak, or who knows? Either way, I think ammunition (caseless) and propellant would be the largest changes possible. Everything else is incremental.
Caseless ammo would necessitate a new weapon altogether....
Based on what metric, and which setting?
Why are the industry leaders in polymer accessories not building free float polymer AR handguards, if this issue is so serious as to pose a safety hazard to the user or the equipment?
Are there properties provided by using a metal on that specific component, that can not be replicated by using polymer? I am thinking countering recoil forces on accessories, zero retention issues, mounting rigidity, altered cook off threshold etc.
The three hottest areas on the gun are the chamber, the barrel and the gas block. The handguard will heat up through radiation, and all components lose heat through convection.
I have not fired an M16A1 (or similar), so I don't know how hot the handguard got, but the G3 handguard could get plenty hot from shooting, and it is plastic.
Price. polymers with the required stiffness for a free-float handguard are expensive. You also have to understand that 90% of the AR shooting, and free-float buying public are casual shooters that rarely get the barrel hot enough for metal handguards to be come uncomfortable. And the military is going to wait until the powered rail interface is standardized, or dropped, before they start spendiing lots of money on the "next great thing".
No, handguards gain heat from convection, conduction and radiation and all parts lose heat through radiation as well as convection.
With the radiation shields in the handgaurds, the M16A1 and A2 do a reasonable job of keeping the handguards fron becoming uncomfortable except under the most extreme rates of fire. At maximum continuous rate of fire you'll never have a problem.
Mistwolf- I definitely agree that polymer is better for the unclothed human to interact with than any metal alloy we have seen yet in FFR's. But is polymer capable of maintaining the precise attachment that is needed for things like lasers and optics? Some real end users do more than just Costa grip their rails and need a rail that will hold zero.
a carbon-fiber tube is stiffer that a comparable size aluminum tube. So a properly designed and manufactured CFRP free-float is going to be better....as well as lighter.
You're developing a machine that... throws people out of windows? :blink:
So far, this is what I'm getting: Materials development and ammunition (specifically propellant chemistry).
What about the long tail of the bolt carrier, which requires the use of a long spring and receiver extension? There are a few buffer and carrier systems out there that greatly reduce this dimension, but still seem to be "relatively untested Boutique accessories." e.g. the Troy M7A1 PDW (https://troyind.com/products/pdw-stock-kit-blk) stock, MVB ARC (https://mvbindustries.com/product/arc-stock/) stock, or NEA CCS (http://www.neaginc.com/3_accessories.html) stock; and the ARES Defense SCR (http://www.aresdefense.com/?page_id=729).
If you start doing that, you are making a new design....
As I stated early in this thread, there isn't anything really wrong with the basic design. A few minor tweaks in the areas of accessory mounting (may as well wait for the STANAG powered rail to be standardized), but other than that, leave it alone.
If you really fell the need for something "better" get a clean sheet of paper and design something better.
sinlessorrow
05-09-15, 21:31
Price. polymers with the required stiffness for a free-float handguard are expensive. You also have to understand that 90% of the AR shooting, and free-float buying public are casual shooters that rarely get the barrel hot enough for metal handguards to be come uncomfortable. And the military is going to wait until the powered rail interface is standardized, or dropped, before they start spendiing lots of money on the "next great thing".
No, handguards gain heat from convection, conduction and radiation and all parts lose heat through radiation as well as convection.
With the radiation shields in the handgaurds, the M16A1 and A2 do a reasonable job of keeping the handguards fron becoming uncomfortable except under the most extreme rates of fire. At maximum continuous rate of fire you'll never have a problem.
And the M16A1 had 170 rounds before cookoff while the current M4A1 has something closer to 240 rounds before cookoff. Actually I believe with the M4 they went from 170 to 210 by just going to the RIS. So far the only argument for polymer rails is "I don't want to wear gloves" despite the numerous advantages of aluminum rails.
Also with the M4A1+ requirement coming out I find your first part hold no water. The Army wants a FF rail, with addon rail panels, that offers enhanced zero rentention while also keeping weight of the rifle below 8lbs. Should be the perfect time to develop a super duper high tech polymer rail...I bet we see none entered.
Also powered rail...*Snickers*. Nothing like having every ancillary item on your rifle go down at the exact same time due to the battery.
And the M16A1 had 170 rounds before cookoff while the current M4A1 has something closer to 240 rounds before cookoff. Actually I believe with the M4 they went from 170 to 210 by just going to the RIS. So far the only argument for polymer rails is "I don't want to wear gloves" despite the numerous advantages of aluminum rails.
Also with the M4A1+ requirement coming out I find your first part hold no water. The Army wants a FF rail, with addon rail panels, that offers enhanced zero rentention while also keeping weight of the rifle below 8lbs. Should be the perfect time to develop a super duper high tech polymer rail...I bet we see none entered.
Also powered rail...*Snickers*. Nothing like having every ancillary item on your rifle go down at the exact same time due to the battery.
The cook-off numbers went up because of this:
http://www.guns.com/wp-content/uploads/2014/03/m4-m4a1-barrel-profiles.jpg
The M4 with the original barrel profile did not see any improvement, M4s have been re-barreled with the new profile, these have higher rounds-to-cook-off numbers.
The M4A1+ is a non-developmental program, it's an "off-the shelf" buy. It is not the "next great thing", it's the place-holder until the "next great thing".....
Unless you have insider information, nobody knows as the Army has yet to release who and what has been submitted.
Nothing like having supply send you twelve AAs, when what you needed was two AA, six CR-123, and four CR2032s...
You've dealt with the Army supply system, haven't you?
sinlessorrow
05-10-15, 00:21
The cook-off numbers went up because of this:
http://www.guns.com/wp-content/uploads/2014/03/m4-m4a1-barrel-profiles.jpg
The M4A1+ is a non-developmental program, it's an "off-the shelf" buy. It is not the "next great thing", it's the place-holder until the "next great thing".....
Unless you have insider information, nobody knows as the Army has yet to release who and what has been submitted.
Nothing like having supply send you twelve AAs, when what you needed was two AA, six CR-123, and four CR2032s...
You've dealt with the Army supply system, haven't you?
Barrel diameter does not account for why the M4 went from 170 rounds before cookoff to 210 after the KAC RIS was adopted.
So you would rather have a battery in the stock of your rifle that powers your NV, Laser, Light, Optic? Than individual powered items? By going to a powered rail system you would greatly reduce the battery life of say the M68-CCO due to the power drain of NV, lights, and lasers. All of which require significant power to keep running.
Me and Arctic1 don't usually agree on anything, but he was spot on in what he posted earlier. Frankly Metal rails just do things polymer ones do not.
Barrel diameter does not account for why the M4 went from 170 rounds before cookoff to 210 after the KAC RIS was adopted.
So you would rather have a battery in the stock of your rifle that powers your NV, Laser, Light, Optic? Than individual powered items? By going to a powered rail system you would greatly reduce the battery life of say the M68-CCO due to the power drain of NV, lights, and lasers. All of which require significant power to keep running.
Me and Arctic1 don't usually agree on anything, but he was spot on in what he posted earlier. Frankly Metal rails just do things polymer ones do not.
Show me where it did, and by how much.
I would rather the the supply system is always stocked with the type of batteries I need, and I don't care if it is in the stock, pistol grip or magically sends power to my accessories from my pocket. And, a single battery in a single easy to access battery well can be replaced more easily than three or or four separate batteries here and there on the weapon. An Aimpoint lasts 8 years on a single AA, that's not a high drain item that is almost incidental to the system, the average NVS gets about 40 hours to a battery, if you are only powering those two, you will still only get about 40 hours. The big drain is the PEQ, and that should have a new battery after every operation that requires it.
Advantages:
1) simpler supply system, only need one battery.
2) simpler operator maintenance, only need to replace one battery, and only need one type of battery
3) improved storage requirements, no batteries in the individual items
4) overall saving in weight.
5) removing components removes drain from the battery
Disadvantages:
1) If you're not smart, everything fails at once. Of course, if you're in the dark and your PVS battery goes dead that fully powered red-dot is not of much use...
People used to say the same thing about polymer pistol frames....
Show me where it did, and by how much.
I would rather the the supply system is always stocked with the type of batteries I need, and I don't care if it is in the stock, pistol grip or magically sends power to my accessories from my pocket. And, a single battery in a single easy to access battery well can be replaced more easily than three or or four separate batteries here and there on the weapon. An Aimpoint lasts 8 years on a single AA, that's not a high drain item that is almost incidental to the system, the average NVS gets about 40 hours to a battery, if you are only powering those two, you will still only get about 40 hours. The big drain is the PEQ, and that should have a new battery after every operation that requires it.
Advantages:
1) simpler supply system, only need one battery.
2) simpler operator maintenance, only need to replace one battery, and only need one type of battery
3) improved storage requirements, no batteries in the individual items
4) overall saving in weight.
5) removing components removes drain from the battery
Disadvantages:
1) If you're not smart, everything fails at once. Of course, if you're in the dark and your PVS battery goes dead that fully powered red-dot is not of much use...
People used to say the same thing about polymer pistol frames....
You could also program the powered rails to cut power to certain systems in battery saver mode when charge gets low like your cell phone.
Price. polymers with the required stiffness for a free-float handguard are expensive. You also have to understand that 90% of the AR shooting, and free-float buying public are casual shooters that rarely get the barrel hot enough for metal handguards to be come uncomfortable. And the military is going to wait until the powered rail interface is standardized, or dropped, before they start spendiing lots of money on the "next great thing".
I am quite aware. The use of gloves was brought up as an issue, and that was the specific point I was adressing. I don't think the issue is as big as some make it out to be, re metal handguards and temperature issues.
I saw Lancer Systems has CF handguards, and as you say they were quite expensive:
http://store.lancer-systems.com/category/carbon_fiber_handguards
That said, I'm not quite convinced that price is the sole reason why they are not currently in use by mil. I think there is more to it.
No, handguards gain heat from convection, conduction and radiation and all parts lose heat through radiation as well as convection.
Convection? The handguard has no properties that draws heat away from the barrel (unlike air or water). Some of the heat transfer is from conduction via the barrel nut, and some through radiation. True that some heat is lost through radiation, but the main means of cooling these weapons is through convection - air cooling.
With the radiation shields in the handgaurds, the M16A1 and A2 do a reasonable job of keeping the handguards fron becoming uncomfortable except under the most extreme rates of fire. At maximum continuous rate of fire you'll never have a problem.
The G3 also has a "radiation shield", but still gets plenty hot. The 7.62 does produce more heat energy.
The G3 also has a "radiation shield", but still gets plenty hot. The 7.62 does produce more heat energy.
It's not that polymer handguards will not get hot, it's that metal handguards will burn your hands while the polymer handguards will be uncomfortably warm under the same conditions. I can tell you from experience, the thin barrel of a G3 pattern rifle will get hot quick
It's not that polymer handguards will not get hot, it's that metal handguards will burn your hands while the polymer handguards will be uncomfortably warm under the same conditions. I can tell you from experience, the thin barrel of a G3 pattern rifle will get hot quick
I know it get's hot, as I said I was issued one for several years. I actually burned my arm after a break contact drill, coming in contact with the barrel for a split second.
As to burning you hands on a metal hand guard, not sure I agree with that assertion. Sorry.
Oh good grief! I don't care if you buy it or not, but your assertions do not change the laws of physics. Aluminum will transfer heat to and from your skin much quicker than the polymer materials used to make modern quality handguards.
Are pots and pans made from polymer? Or aluminum? Which is easier to drink hot coffee from- a tin cup? Or a plastic (polymer) cup? Why do you think the "chicken mitt" (an oven glove shaped like a chicken) is a running joke on the FalFiles when the subject of StG-58 stamped steel handguards comes up?
I was an aviation technician before you were itching your daddy's pants and turning wrenches on cars and shooting before that. I've learned a thing or two along the way about PPE and what affects heat, cold, dust, vibration, kneeling, squatting, lifting and so on have on the body. The bottom line is, it doesn't matter how some young whipper-snapper thinks something works because all that thinking in the world won't change how it actually works
(Oh crap, did I just use the phrase "itching your daddy's pants" and "young whipper snapper"? I think I'm turning into an Old Curmudgeon)
Oh good grief! I don't care if you buy it or not, but your assertions do not change the laws of physics. Aluminum will transfer heat to and from your skin much quicker than the polymer materials used to make modern quality handguards.
Are pots and pans made from polymer? Or aluminum? Which is easier to drink hot coffee from- a tin cup? Or a plastic (polymer) cup? Why do you think the "chicken mitt" (an oven glove shaped like a chicken) is a running joke on the FalFiles when the subject of StG-58 stamped steel handguards comes up?
I was an aviation technician before you were itching your daddy's pants and turning wrenches on cars and shooting before that. I've learned a thing or two along the way about PPE and what affects heat, cold, dust, vibration, kneeling, squatting, lifting and so on have on the body. The bottom line is, it doesn't matter how some young whipper-snapper thinks something works because all that thinking in the world won't change how it actually works
(Oh crap, did I just use the phrase "itching your daddy's pants" and "young whipper snapper"? I think I'm turning into an Old Curmudgeon)
Excellent argument.
You assertion was this:
it's that metal handguards will burn your hands
That is pure and utter bullshit.
I don't care that you are much older than me (although I doubt you know my age); and the fact that you are using snide remarks in your argument really shows your maturity.
I can back up my assertions with thousands of shooters over many, many years who have not burned their hands on either metal or polymer/plastic handguards. Handguards do not get that ****ing hot! Why is that so hard to understand?
If the handguard getting uncomfortably hot is an issue for you, then start shooting with gloves. Your personal anecdotal experience on this matter doesn't equate to this being a big issue.
If you are shooting so much that you cannot hold the rifle, then you are probably way over the recommended rate of fire any ways. The only weapon I have shot, where the handguard got extremely hot, was the Honey Badger (after many people had shot it before me).
Not even on a machinegun used in a sustained fire role, shooting several hundred rounds in a short time frame, does the handguard or barrel casing get too hot to carry.
But what do I know, right?
This a forum for discussion; you should expect that people can actually disagree with something you say.....
Dionysusigma
05-10-15, 15:36
:rolleyes: Y'all are getting cranky about a hypothetical discussion on the internet... and if the AR was so great to begin with, why are there thousands of changes and upgrades available on the market today (not to mention obsolete or failed ideas) allowing the extensive customization the platform is known for?
Back to rationality:
So, excess heat from the propellant makes the weapon unpleasantly warm after a period of use, regardless of what the handguard is made of. That heat has to go somewhere. Water-cooling hasn't been a thing since WW1, for good reason. Would some sort of active fan system (something small, like from a laptop) continually moving air from the rear of the rail to the front (ie away from the user) help this issue at all? Sure, another doodad to hang off the gun, but could it possibly work? Maybe as an integrated component of the Powered Rail system?
Or maybe someone could try an idea like a detachable heat sink from the Mass Effect games...
Heat from the propellant and hot gases, but also heat from the contact/friction between the projectile passing through the barrel.
One common approach to help cooling is to increase the surface area of the barrel - dimpling or fluting. I think the jury is out on the actual effectiveness. It does reduce the weight of the barrel itself.
A thicker barrel profile doesn't reduce the generated heat, but makes the barrel more resilient to the effects of heat - it also adds weight.
Everyone lighten up a little, mmmkay? It's an internet argument.
You are literally validating that these are indeed issues. The fact that you're saying, "Oh, just wear gloves" is a little off; the point of the discussion is correcting the issues themselves, not methods with which we can ignore them.
No I didn't.
Locking the bolt back is very easy on the AR/M4. If you have an issue with that, well you need more training.
The Magpul BAD lever is a mod/accessory to make this process easier, but I have never installed one in any of my rifles.
Wearing gloves is for protection, just as you would wear eyes, ears, vest, helmet or a hat (based on your needs). You do not need gloves with polymer handguards though, so I don't know what your point was going with that argument. Wearing gloves is beneficial if you have metal/aluminum handguards and you plan to shoot a large amount of ammo. It is also helpful in the cold and wet environments, but is not a must.
Heat from the propellant and hot gases, but also heat from the contact/friction between the projectile passing through the barrel.
One common approach to help cooling is to increase the surface area of the barrel - dimpling or fluting. I think the jury is out on the actual effectiveness. It does reduce the weight of the barrel itself.
A thicker barrel profile doesn't reduce the generated heat, but makes the barrel more resilient to the effects of heat - it also adds weight.
You could put a aluminum heat sink on the barrel:
http://jprifles.com/photos_new/heatsink.jpg
Then leave it open on the back end and then extend the barrel shroud beyond the muzzle so the muzzle blast causes air to flow through the fins and cool the barrel... Wait, that's been done. Worked pretty good at allowing for a higher sustained rate of fire, but the shroud got pretty hot as well....
http://photos.imageevent.com/badgerdog/generalstorage/lewisgunarticle/large/1.%20Pattern%201914%20Lewis%20Gun%20fitted%20with%20No%205%2047%20round%20magazine%20and%20MkIII%20Field%20Mount.jpg
I think we should hypothetically examine improvements to the Lewis gun. My first suggestion would be some sort of durable mini-dirigible to help tote the 28 pound beast.
rcoodyar15
05-15-15, 17:18
Another thought for the CNC guys. Make a new AR. Half way between the AR15 and AR10. Mag length 2.55? That way you could use all those 6mm wildcats at mag length. A dasher AR that magazine feeds!
I have been thinking a lot about the design of the AR receiver/barrel connection myself. This system was not originally designed for 26" 5.5# barrels.
Wonder if anyone will ever design an upper with a whole lot more meat at the receiver/barrel connection? Wonder if it would be possible to thread the receiver/barrel connection like a bolt gun? Tony Kidd is doing it with his 10/22 receivers. It would certainly be a niche market. Bet it would improve accuracy. With todays CAD milling machines it shouldn't be that hard. Varmint and long range guys would like it though.
Another thought for the CNC guys. Make a new AR. Half way between the AR15 and AR10. Mag length 2.55? That way you could use all those 6mm wildcats at mag length. A dasher AR that magazine feeds!
I have been thinking a lot about the design of the AR receiver/barrel connection myself. This system was not originally designed for 26" 5.5# barrels.
Wonder if anyone will ever design an upper with a whole lot more meat at the receiver/barrel connection? Wonder if it would be possible to thread the receiver/barrel connection like a bolt gun? Tony Kidd is doing it with his 10/22 receivers. It would certainly be a niche market. Bet it would improve accuracy. With todays CAD milling machines it shouldn't be that hard. Varmint and long range guys would like it though.
Are you going to make your own mags then? Seems like that might be a little tricky.
Are you going to make your own mags then? Seems like that might be a little tricky.
I would think that if you control the design of the weapon, getting the mags right would be one of the less difficult parts. Especially with manufacturers like Magpul out there. Also, I know nothing about design, so this opinion is worth what you paid for it. :)
I would think that if you control the design of the weapon, getting the mags right would be one of the less difficult parts. Especially with manufacturers like Magpul out there. Also, I know nothing about design, so this opinion is worth what you paid for it. :)
I've no doubt that Magpul could do it but I got the impression he wants to make a prototype.
Don't forget how much time it took to develop reliable 30 round 5.56 mags though.
I've no doubt that Magpul could do it but I got the impression he wants to make a prototype.
Don't forget how much time it took to develop reliable 30 round 5.56 mags though.
I don't know the results from it, but I believe that Magpul has made intermediate sized 6.8 SPC mags that were/are proprietary to LWRC's platform.
rcoodyar15
05-16-15, 11:47
I've no doubt that Magpul could do it but I got the impression he wants to make a prototype.
Don't forget how much time it took to develop reliable 30 round 5.56 mags though.
I don't want to make a prototype. It would be nice to see one of the receiver manufacturers take this project on. These days if you can get it on paper then those CNC machines can make it. If you have the equipment then the only extra expense you would have would be tweaking the design in cad. Stretching an AR15 lower a quarter of an inch and leaving the barrel attachment part of the receiver full thickness should not be that difficult. Neither would threading that chunk of aluminum for the barrel to thread into. Milling out the locking lug recess in the barrel should be no different than milling it out in a barrel extension.
I am sure there are those out there who would make custom mags for a price. Like you say the mags would take some work but I am sure reliable mags could be made.
Just a Hypothetical. Maybe someone will like the idea and do it. Tony Kidd is threading his receiver barrel connection for his supergrade 10/22
I sure would like to have a super accurate AR-Dasher that would magazine feed.
vicious_cb
05-16-15, 23:14
You could put a aluminum heat sink on the barrel:
Then leave it open on the back end and then extend the barrel shroud beyond the muzzle so the muzzle blast causes air to flow through the fins and cool the barrel... Wait, that's been done. Worked pretty good at allowing for a higher sustained rate of fire, but the shroud got pretty hot as well....
Aluminum heat sinks are a joke, you dont have enough surface contact with the barrel to make the thermal transfer efficient enough for it to be worth it and you would be screwing with the barrel harmonics. You would have to either machine the cooling fins into the barrel itself or use some kind of metallic thermal paste to glue the heat sink to the barrel.
Aluminum heat sinks are a joke, you dont have enough surface contact with the barrel to make the thermal transfer efficient enough for it to be worth it and you would be screwing with the barrel harmonics. You would have to either machine the cooling fins into the barrel itself or use some kind of metallic thermal paste to glue the heat sink to the barrel.
Apparently, you can't recognize a joke when you read one....
Dionysusigma
05-17-15, 14:27
When it comes to R&D, the only difference between a joke and a project is funding.
I think the Lewis Gun had a good concept, were it not for the fact that it relied on the pressure of the round exiting the barrel and shroud to pull cooling air through. A constant forced-air design might work, though, with vicious_cb's machined-in barrel fins (or, deep fluting).
vicious_cb
05-17-15, 17:46
Apparently, you can't recognize a joke when you read one....
Apparently not since companies still keep making products like this :rolleyes:
http://www.thefirearmblog.com/blog/wp-content/uploads/2013/12/ar-fin.jpg
Also you need to be more obvious with your jokes. Like this:
http://a.disquscdn.com/uploads/mediaembed/images/759/5321/original.jpg
Is it bad that I want one of those now?
That's actually pretty badass.. Just saying lol.
Aluminum heat sinks are a joke, you dont have enough surface contact with the barrel to make the thermal transfer efficient enough for it to be worth it...
Yet an aluminum handguard which only makes contact with the barrel through the barrel nut reduces chamber heat.
Everything screws with barrel harmonics- gas block, muzzle device, suppressor, gas tube, barrel profile, ammo, barrel nut torque, hanguards- yet we manage to put bullets on target anyway
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