View Full Version : How I chose a caliber for an AR rifle
Rather than post in another thread, I figured this might be an opportunity, both for myself and others, to explain their decision making on this choice.
History: I spent about 30 years in the US government's military, first shooting an AR rifle in 1967. The details are somewhat fuzzy, except that I remember than it was an early one sans forward assist, that's what the Air Force purchased way back then. I also remember how easy it was to shoot accurately on the 100 yard range, despite the obvious wear these rifles had acquired as a basic training weapon.
Moving forward, I spent quite a bit of time on an M16 qualification range, courtesy of the four day Range Safety NCO course at Fort Bragg, and being designated range safety NCO for six years running in my Army National Guard unit during the 1980's and early 90's.
Details: I've always liked the form factor of the AR/M16, but that caliber was always a stopper for me personally. I don't want to turn this into a 5.56/7.62 discussion, but for me the 7.62 was the choice for anyone defending their home against a determined adversary. While I have an M14/M1A type rifle, my choice for actual use was the FAL. I built one for myself, and one each for my two brothers. That was that, I thought, I'd just have to tolerate the 12+ pounds of rifle. After considering a modernization of the M14, and seeing that it would weigh in at over 13 pounds, possibly over 14 pounds, I nixed that idea. Before acquiring the M14 and FAL, I had considered the AR10 from Armalite. The stopper there was price, compared to the FAL, and Armalite's notorious customer service, or lack of it, and the notion that you'd be stuck with modifying M14 magazines yourself, or buying the ridiculously expense Armalite units, to have a functional rifle. I passed on that.
Now: Then, a few years ago, I began reading about the new calibers available for the standard AR receiver. That interested me, so I kept an eye on development. I don't like the idea of being a beta tester for a life support device and that's what these rifles really are, so I waited for them to be developed further.
I weighed the two rounds that floated to the top, the 6.8 SPC and the 6.5 Grendel and decided this year on the latter. One reason, admittedly not a great one, is that the .270 caliber is historically a bastard 7mm bore cooked up by Winchester so that they could have a solidly proprietary cartridge and have a virtual monopoly on components. They accomplished that and it lasted for decades, pushed by the late Jack O'Connor of Outdoor Life Magazine. If it wasn't for O'Connor and Winchester, I dare say we'd not see any bullets between the 6.5mm and 7mm, but that's water under the bridge, well and truly.
My other, much more solid reasons, are that the 6.5 Grendel is still on the upward side of the development curve which means that it's going to continue to get better as time goes by. The bullets for this caliber are plentiful, ranging from light varmint bullets, to 140 grain low drag bullets. Hornady has developed a specific 123 grain bullet that they think is optimum for the 6.5 Grendel, at least for now. There are at least three other ammo manufacturers making ammo in 6.5 Grendel, so the shortage of resources has been answered I think. EDIT: I just ordered sufficient 6.5 Grendel magazines for the rifle at 11.99 each, they're C Products, the only source as far as I know, but that's pretty reasonable. That's the same price 5.56 NATO mags are.
The other thing that struck me was that the 6.5 Grendel varied between merely very good to simply outstanding at any range between the muzzle and 1100 yards. The 6.8 SPC was close, and quite interesting, but why go that route when there's the Grendel? I couldn't think of a reason. The rifles were the same cost wise, both took the usual AR accessories if one wants them, so my choice was made.
I should have this rifle built by the end of January.
Will I get rid of my 7.62NATO rifles? Nope, they have their place. But for a lightweight, easy to carry rifle, with 75% more muzzle energy than the 5.56NATO, the 6.5 Grendel has a lot going for it.
Thomas M-4
11-30-09, 14:29
First off I respect your opinion and I my self have wanted to build a rifle chambered in 6.5 Grendel or 6.8 spc and when I first had the notion to build one I got tangled up in the 6.5 vs 6.8 debate then I came to realize the debate 6.5 vs 6.8 was hog wash both cartridges were designed to do two different things so what was the point of the debate:rolleyes:
If I wanted to build a 16'' or shorter combat rifle it would be 6.8 SPCII chamber with ammo loaded to take full advantage of the spec II chamber 6.8 performs best with 16'' and shorter barrels Another reason I see reports that the 6.8 spc is easier to feed through a automatic action. Just the ticket for a compact rifle that packs the punch of a main battle rifle;)
The 6.5 is a accurate long range cartridge perfect for a SPR , style long range longer barreled rifle in the ar-15 platform.With the very high BC of the 6.5mm bullets the 6.5 will always be a top performer at long ranges.
First off I respect your opinion and I my self have wanted to build a rifle chambered in 6.5 Grendel or 6.8 spc and when I first had the notion to build one I got tangled up in the 6.5 vs 6.8 debate then I came to realize the debate 6.5 vs 6.8 was hog wash both cartridges were designed to do two different things so what was the point of the debate:rolleyes:
If I wanted to build a 16'' or shorter combat rifle it would be 6.8 SPCII chamber with ammo loaded to take full advantage of the spec II chamber 6.8 performs best with 16'' and shorter barrels Another reason I see reports that the 6.8 spc is easier to feed through a automatic action. Just the ticket for a compact rifle that packs the punch of a main battle rifle;)
The 6.5 is a accurate long range cartridge perfect for a SPR , style long range longer barreled rifle in the ar-15 platform.With the very high BC of the 6.5mm bullets the 6.5 will always be a top performer at long ranges.Which type 6.8 SPC did you build or acquire?
Thomas M-4
11-30-09, 17:56
Which type 6.8 SPC did you build or acquire?
My current plan is to start on it picking up parts first of next year.
Novoske 16'' barrel in 6.8 SPCII chamber
Mega upper and lower receiver
KAC URXII rifle length railed FF hand guard
Eventually I would like to top it off with a TA31H-68: 4x32 Trijicon ACOG optic.
Unfortunately this will be a long term project for me once I do start do to money being tight at this time.
I have already acquired reloading equipment which should allow me to be able to shoot it more once I do get it finished.
Grendelizer
11-30-09, 21:32
the 6.5 will always be a top performer at long ranges.
The 6.5 Grendel also performs exceptionally at typical combat ranges of 0-300. To say that it's best reserved for long range is the equivalent of an urban myth.
John
Thomas M-4
12-01-09, 09:51
The 6.5 Grendel also performs exceptionally at typical combat ranges of 0-300. To say that it's best reserved for long range is the equivalent of an urban myth.
John
Are you trying to bait me? I never said it did not perform from 0-300??:rolleyes:
I'd like to suggest that when each cartridge was designed, one important criteria was whether it would have to function in a linked belt MG. 6.8, yes, 6.5, no.
That has nothing much to do with each rounds inherent application - which are different. It does have a lot to do with logistics and interoperability at the squad and platoon level. Honestly, not an issue to the average civilian shooter.
What does have an impact is the notion that a superior long range cartridge will be used that way. The whole point of the invention of the assault rifle is based on the researched and documented use of rifles in combat in short range engagements - not long range. The majority of kills by soldiers were within 400 yards or less. Add the higher rate of fire documented to put down more soldiers, and you get an intermediate round - not long range precision.
Basically, the higher BC effect isn't seen in combat, and is therefore a wasted resource when fielded to every soldier. When the range is needed, the .308 is in the system and used.
For the civilian shooter, again, much of that is moot - except for the actual use by them at long ranges. Some can and do, most don't shoot over 250 yards.
The average shooter will never consistently use the capability. It's like the pickup truck they drive daily to work, alone, with nothing in the bed. Wasted capacity.
That's the way staff studies saw the main battle rifle calibers, and the principles involved still apply to a choice between 6.8 or 6.5 - althought to a much more minor degree. Nonetheless, if long range is the goal, the 6.5 is the better choice - in that limited use.
Most would be well served with the 6.8, and that's part of the thinking I used in choosing it.
Grendelizer
12-01-09, 10:35
I'd like to suggest that when each cartridge was designed, one important criteria was whether it would have to function in a linked belt MG. 6.8, yes, 6.5, no.
You have no evidence for this. Simply making it up?
The whole point of the invention of the assault rifle is based on the researched and documented use of rifles in combat in short range engagements - not long range.
If you've been following the latest developments, there is an ongoing effort to get weapons that hit harder at longer range. Thus, for example, the move to get M-14s back to the troops as a stop-gap measure.
Basically, the higher BC effect isn't seen in combat, and is therefore a wasted resource when fielded to every soldier. When the range is needed, the .308 is in the system and used.
Um, no. Military bullets use the highest BC they can, balanced by any competing factors. Witness the 7.62 147gr of M80 NATO.
For the civilian shooter, again, much of that is moot - except for the actual use by them at long ranges. Some can and do, most don't shoot over 250 yards.
Civilian 6.5 Grendel shooters have a wide variety of 6.5mm bullet options, including the option to "dumb down" the 6.5 Grendel with lower BC 6.5mm bullets if, for some reason, they want to match the ballistics of the 6.8 SPC.
The average shooter will never consistently use the capability. It's like the pickup truck they drive daily to work, alone, with nothing in the bed. Wasted capacity.
Your analogy is faulty. Military engagements vary, and it pays to be ready for anything. Better to have the capability (at no extra penalty) and not need it, than to need it and not have it.
Further, an assault rifle cartridge should be used not only in ARs, but also in machine guns and light sniper rigs, where you need to hit hard at long-range.
That's the way staff studies saw the main battle rifle calibers, and the principles involved still apply to a choice between 6.8 or 6.5 - althought to a much more minor degree. Nonetheless, if long range is the goal, the 6.5 is the better choice - in that limited use.
The top tier of our nation's special operations forces have downselected the 6.5 Grendel as their only choice, should they be authorized to develop and field an intermediate cartridge. We have this directly from their mouths. I don't know what "principals involved" you're referring to.
Most would be well served with the 6.8, and that's part of the thinking I used in choosing it.
This is true. Most civilians shooting paper or deer at 100 yards will be just fine with either one.
But because the 6.5 Grendel can do everything the 6.8 SPC can do, yet the 6.8 SPC cannot do everything the 6.5 Grendel can do, for military use, it's 6.8 SPC: Fail. 6.5 Grendel: Win.
John
I am really growing tired of the internet debate on the 6.x's....
If this thread makes me regret posting here, knowing how it will go, I am probably going to lock some accounts.
So be forewarned that you guys can and will discuss this like mature, armed adults, at a friendly gathering.
Okay? Good.
Are you trying to bait me? I never said it did not perform from 0-300??:rolleyes:
I dont think he was, he was just adding to the fact the 65 performs long and short.
I'd not want to be shot at short range with a 6.8 SPC or 65. Thats really the LONG and SHORT of it :D
I'd like to suggest that when each cartridge was designed, one important criteria was whether it would have to function in a linked belt MG. 6.8, yes, 6.5, no.No, that's not true. Neither was designed with that in mind because designing a link for a disintegrating belt is no more than an engineering exercise. There is no evidence, of any kind, that the 6.5 Grendel won't function in a belt-fed weapon.
That has nothing much to do with each rounds inherent application - which are different. It does have a lot to do with logistics and interoperability at the squad and platoon level. Honestly, not an issue to the average civilian shooter.The 6.5 Grendel will fill the military requirement just fine. However, you are correct, belt-fed's are a pretty esoteric use.
What does have an impact is the notion that a superior long range cartridge will be used that way. The whole point of the invention of the assault rifle is based on the researched and documented use of rifles in combat in short range engagements - not long range. The majority of kills by soldiers were within 400 yards or less. Add the higher rate of fire documented to put down more soldiers, and you get an intermediate round - not long range precision. [/q2uote]When you know that the 6.5 Grendel fulfills both arenas, why not go to it? There's nothing between 0-300 that the 6.5G won't do, yet, there's plenty in the 300-1100 that the "other" cartridge won't do.
[quote]Basically, the higher BC effect isn't seen in combat,Yes, actually, it is seen. The development of the spitzer bullet shape was a major milestone in rifle bullet design.
and is therefore a wasted resource when fielded to every soldier. When the range is needed, the .308 is in the system and used. It is now because nothing better is available. The 6.5G is better than the .308 ballistically.
For the civilian shooter, again, much of that is moot - except for the actual use by them at long ranges. Some can and do, most don't shoot over 250 yards.But the capability is there is you want it. That's like my car, it has enough power to push the car to 140+, I don't use that very often, but it's there when I want to call on it.
The average shooter will never consistently use the capability. It's like the pickup truck they drive daily to work, alone, with nothing in the bed. Wasted capacity.
That's the way staff studies saw the main battle rifle calibers, and the principles involved still apply to a choice between 6.8 or 6.5 - although to a much more minor degree. Nonetheless, if long range is the goal, the 6.5 is the better choice - in that limited use.
Most would be well served with the 6.8, and that's part of the thinking I used in choosing it.What I was looking for in this thread isn't a comparison between the two cartridges, I wanted to know the process you used to choose. I wanted to include ALL calibers, not just the two competing ones.
However, since I did mention why I didn't select the 6.8 SPC, all's fair game. :)
Just curious, What kind of velocity would you get with a 10.5" barrel 6.5 vs a 6.8?
Is the 6.8 better for short barrel and 6.5 for long barrels?
What I'm getting at is would the 6.5 preform in that short of barrel?
Thanks
Just curious, What kind of velocity would you get with a 10.5" barrel 6.5 vs a 6.8?
Is the 6.8 better for short barrel and 6.5 for long barrels?
What I'm getting at is would the 6.5 preform in that short of barrel?
ThanksI haven't seen either chronographed from a short barrel, I'd expect them both to suffer around 150-200 fps velocity loss at that lenght, so I'd guess you could interpolate the velocity from that measured from 16 inch barrels.
I'd rate them both as extremely lethal from a short barreled rifle, both would send a projectile down range at something over 2000 fps.
I am just finishing my first Grendel build. AA upper, lower, and 16 in stainless barrel with matched bolt. RRA two stage trigger, free float tube and A2 stock. Hope to finish up this month and get to the range. 6.8 and 6.5 are both a definite step up from 5.56 but I like the better bullet choices of the 6.5
I just finished building my lower receiver, now if I can just hold out for the upper to arrive. :p
Photos tomorrow.
"I haven't seen either chronographed from a short barrel, I'd expect them both to suffer around 150-200 fps velocity loss at that lenght, so I'd guess you could interpolate the velocity from that measured from 16 inch barrels."
As first posted a couple of years ago:
SSA 2nd generation SAAMI pressure 115 gr SMK OTM w/cannelure, 5 shot averages:
20” barrel: ave vel = 2561 fps; 10 fps extreme spread
16” barrel: ave vel = 2525 fps; 18 fps extreme spread -- lost 36 fps from 20"
12.5” barrel: ave vel = 2384 fps; 12 fps extreme spread -- lost 141 fps from 16"
10” barrel: ave vel = 2265 fps; 27 fps extreme spread -- lost 119 fps from 12.5"
7.5” barrel: ave vel = 2035 fps; 27 fps extreme spread -- lost 230 fps from 10"
Obviously the 85-100 gr loads are going substantially faster...
I did find some 6.5 Grendel ballistics for 14.5 & 16 inch barrels.
123 gr. Lapua OTM muzzle then 500 yds then 1000 yds
16 inch 2480 fps 1761 1226
14.5 in. 2405 fps 1700 1189
Photos as promised. Without the upper, velocity is nil. ;)
http://images24.fotki.com/v768/photos/5/41655/8123914/6_5Grendel_05-vi.jpg
http://images47.fotki.com/v1589/photos/5/41655/8123914/6_5Grendel_15-vi.jpg
I don't see it as an argument of fail/win. Ballistics isn't a black and white decision where one caliber is hands down the only choice. Asserting that 6.5 is superior to .308 is arguable at best - the military uses .308.
Other than sporting range events, I'm not aware 6.5 had any military use at all. Rather, I'd read from what I construed as knowledgeable users that 6.8 uppers were in use by SF in Afghanistan. What I can agree on is that whoever knows that either way for a fact isn't getting on the internet and naming what units. It's OPSEC - or just a cover for rumor. It won't bother me at all which way that resolves. It is what it is.
The point of the thread was the progression of battle rifle use and what constituted the experience to choose a caliber. Having shot the M16 series as a Reservist for 22 years and simultaneously owning a HK91, I find more similarity in the process than opposition in the choice of caliber.
.308 battle rifles are not light handy carbines. And the 5.56 didn't inspire much confidence as a stopper. Having read the documented histories of both 6.5 and 6.8 as published on the net, the application of ballistics, and actual match up to battle conditions, it didn't see a point in emulating .308 BC's and reach. I do agree that a 6.x in a AR platform would be a much better combination than what I've already used and experienced.
Much of the difference in opinion is whether the longer distance lethality of the 6.5 is needed. I'm taking the DOD view - as accepted in the use of 5.56 out of 14.5 barrels. It's not. The few additional situations where longer reach is necessary is being provided by M14's - but thats less than one in ten, or even one in thirty. The Squad Designated Marksman program reinforces that - it uses a 5.56 AR platform enhanced to function more as a rifle, not carbine. The 5.56 is itself considered sufficient for the role.
That this conflict is having to address the need for longer range contact may be more a result of chopping the M16A2 down to a carbine role rather than an inherent problem with even the 5.56. Propelling a bullet out of longer barrels does a long range job better. The 6.8 was specifically designed and tuned to do that with a 16 barrel. The 6.5 was emphatically not - it was for long range competition through a minimum 20" barrel.
The confusion comes when other users decide to take the cartridge out of context and apply it to the other role. As asked: what are the ballistic facts of using 6.5 out of 14.5 or 16" barrels? I'll add, does a 20 or 24" barrel enhance the 6.8?
Nobody seems to report chronographed figures, which leads me to believe the development of either cartridge is far from over. I believe it will continue to be an interesting discussion until real facts and figures come out.
Then both sides of what constitutes no real argument at all will actually know the same facts.
I don't see it as an argument of fail/win. Ballistics isn't a black and white decision where one caliber is hands down the only choice.
Agreed, both cartridges have their merits, some people just need to beat their chest on the net to justify a purchase for whatever reason, goes on all over the web really, from car forums to shooting forums. Same for the cliched phrases...
The confusion comes when other users decide to take the cartridge out of context and apply it to the other role. As asked: what are the ballistic facts of using 6.5 out of 14.5 or 16" barrels? I'll add, does a 20 or 24" barrel enhance the 6.8?
6.5 Grendel ballistics (http://www.alexanderarms.com/grendel_ballistics.pdf).
6.8 SPC ballistics (http://www.yuntaa.com/FileManager/Download.aspx?ContentID=4839637F63FAAB4CE040A8C0030270ED)
Grendelizer's post here (http://www.ar15.com/lite/topic.html?b=3&f=121&t=271627) on AR15.com (ignore the long opening post, as it's fairly useless for data), the one starting with the pictures of ammo boxes, is full of good information comparing the two out of more pragmatic barrel lengths.
-B
Well, darn the 6.8 XLS file won't open on my little netbook under Works.
Seeing the Grendel's optimum result of 500 foot pounds from a 24 " barrel is achieved with a 123 g Lapua at 900 yards (m?) does point out the long distance side of things.
Short to short, I'll keep looking. That XLS file is probably over at 68forums. I would really like to see a chart showing the various barrel lengths graphed on the same overlay. It would be a quick display showing the optimums of each. I suspect certain results will be confirmed, but know it could very well turn out different. At shorter ranges and barrel lengths, I expect incremental differences at best.
Like many others, I'm an old school .308 user and long time AR carrier. All the competition to provide a better cartridge for the platform won't hurt. By this time next year, a 7mm may be the leading edge - or not.
Meanwhile the 5.56 soldiers on.
That Excel spreadsheet can be found here (http://www.68forums.com/forums/showthread.php?t=476) (Correctly assumed, on 68Forums), as well as an image file of the same. The image file is a tad ungainly, hence my preference for the spreadsheet. The WOA 18", 1:11 twist barrel seems to be very damn good for velocity. I wish more people would post results of both 10-shot velocity average/spread and that same group's accuracy, but that's the science student in me.
Zak at Demigod, LLC also posted some good info (http://demigodllc.com/~zak/firearms/6.8SPC/faq.php) on the 6.8 SPC out of an 18" barrel.
I thought Grendelizor's post on AR15.com with the graphs did a good job demonstrating overlay, but I agree that a chart or several charts showing the M855, M80, and four different Grendel and SPC loads each would be outstanding. I might be tempted to add M118LR just to demonstrated that solid .308 loads will still show better downrange performance than the Grendel and provide an upper limit of performance (to contrast with the lower limit being the M855).
-B
Completed my 6.5 Grendel and posted photos here (https://www.m4carbine.net/showpost.php?p=529409&postcount=58) in the photo thread.
I'll post field test results ASAP.
6.8 if your need is for medium game hunting, LE or home defense
6.5 if your need is for range work, varmint or predator hunting
The superior killing power of the 6.8 is pretty well documented....................
6.8 if your need is for medium game hunting, LE or home defenseWell, this thread wasn't to engender a 6.5 vs. 6.8 debate, that's been done several times in other threads.
6.5 if your need is for range work, varmint or predator hunting
The superior killing power of the 6.8 is pretty well documented....................No, that's simply not true. While I can state categorically that if the 6.5 Grendel did not exist I'd have chosen the 6.8 SPC, however, the 6.5G does exist and is superior in every meaningful way to the 6.8 SPC that I could find, so there was absolutely no reason to make the lesser choice.
Therefore I made the better choice.
On top of that, my long range bolt gun uses 6.5mm bullets, the icing on the cake.
Doubt Doc Roberts, HTR and a slew of dead critters would agree with you...........but we all have our opinions.
Doubt Doc Roberts, HTR and a slew of dead critters would agree with you...........but we all have our opinions.An equal number of "experts" say I'm correct.
Mark LaRue took his elk this year with a 6.5 Grendel AR. While I'm not inclined to use either caliber for elk; white tails, mulies, black bear, hogs, and lesser animals won't ignore the 6.5 Grendel anymore than they've ignored the 6.8 SPC.
As I said, if the 6.5 Grendel didn't exist I'd have chosen the 6.8 SPC, but fortunately the 6.5 Grendel does exist and I made my decision based on the facts as they exist today.
Thomas M-4
12-31-09, 23:20
Look fastpat I at first was a Grendel fan boy. But 300 meters on in the 6.8 has the advantage in 16'' carbine out to 500 meters they are neck to neck only when they surpass the 500 meter mark do I give the Grendel the advantage and then it is using a longer barrel to get the most out out of it. Each has there sweet spot but for a infantry combat rifle I would chose the 6.8 SPC.
Look fastpat I at first was a Grendel fan boy. But 300 meters on in the 6.8 has the advantage in 16'' carbine out to 500 meters they are neck to neck only when they surpass the 500 meter mark do I give the Grendel the advantage and then it is using a longer barrel to get the most out out of it. Each has there sweet spot but for a infantry combat rifle I would chose the 6.8 SPC.Yes, the 6.8 SPC is definitely a better round than the 5.56 NATO. Thanks for the info!
constructor
01-02-10, 14:21
6.5 Grendel using Bill's max loads in a 16" barrel- zeroed at 200yds drops at 300yds.
due to energy being less than 1000ft lbs 300 yds is about max for taking deer or hogs with either the 6.8 or 6.5.
the same temp, pressure line of sight and program used to figure all drops in both calibers.
100 Nosler-2600fps--drop 9.4/801 ft lbs
107 SMK-2545fps-----drop9.5/878ft lbs
123 SMK-2472fps----drop 9.4/1083ft lbs
120TSX-2472fps----drop9.8/984ft lbs
6.8 SPC SSA factory ammo 16" barrel
100 Nosler-2700fps--drop9.0/809ft lbs
110 Nosler-2630fps--drop9.0/939ft lbs
110TSX-2630fps---drop 9.5/856ft lbs ------added
6.8 handloads max
100 Nosler 2950fps---drop 7.4/993ftlbs
110 Nosler 2750fps--drop8.2/1040ftlbs
ETA - On the Nosler website the 100gr SD and BC are reversed so do not use those numbers
ETA- Available factory ammo
6.5 Grendel
Hornady-123 Amax
Wolf -120fmj
-------123 soft point
AA----120 Nosler
-------123 Lapua
-------129 SST
-------90gr TNT
6.8 SPC
Corbon------110 TTSX
--------------115 SMK
--------------115 subsonic
DoubleTap--110 Vmax
---------------115 FMJ
---------------110TTSX
---------------110 OTM
Hornady-----110 Vmax
---------------110 OTM
Rem.---------115 FMJ
---------------115 HPBT
--------------115 corelokt
--------------115SMK
Sellier&Bellot-110 TTSX
-----------------110 Vmax
SSA------------85 TSX------------SSAs loads available in Commercial and Tactical velocities
----------------90 TNT
----------------95 frangable
----------------97 AP
----------------100 Nosler Accubond
----------------110 Nosler Accubond
----------------110 Sierra Pro hunter
----------------110 TTSX
----------------115 SMK
6.5 Grendel using Bill's max loads in a 16" barrel- zeroed at 200yds drops at 300yds.
due to energy being less than 1000ft lbs 300 yds is about max for taking deer or hogs with either the 6.8 or 6.5.
the same temp, pressure line of sight and program used to figure all drops in both calibers.
100 Nosler-2600fps--drop 9.4/801 ft lbs
107 SMK-2545fps-----drop9.5/878ft lbs
123 SMK-2472fps----drop 9.4/1083ft lbs
120TSX-2472fps----drop9.8/984ft lbs
6.8 SPC SSA factory ammo 16" barrel
100 Nosler-2700fps--drop9.0/809ft lbs
110 Nosler-2630fps--drop9.0/939ft lbs
110TSX-2630fps---drop 9.5/856ft lbs ------added
6.8 handloads max
100 Nosler 2950fps---drop 7.4/993ftlbs
110 Nosler 2750fps--drop8.2/1040ftlbs
ETA - On the Nosler website the 100gr SD and BC are reversed so do not use those numbersLooks good, using the 1000 ft.lbs. criteria, the Hornady A-Max 123 gr. factory load would be good to 400 yards. Unfortunately, Hornady chose not to publish the barrel length, perhaps they'll publish that later.
http://images22.fotki.com/v818/photos/5/41655/8298317/65Gre_123Amax-vi.jpg
I have both calibers, as well as many others, including, 243, 6mmTurbo, 300 Whisper, 7.62x39, and 5.45x39. I have purchased 2 6.8spc's though simply because I loved my RRA so much, I had to have another one. My 6.5G is Sabre. I agree with some that a 6.8 is a much better combat rifle, but mine shoots very consistent @ 600m, with an ACOG, and thats not to shabby for a combat rifle , w/ 16" barrel. I like the 6.8 better simply because I can go anywhere and buy ammo, and way more companies are makin it right now. If I wanted to build an auto bench rifle (which I have in .556) I may steer toward the 6.5. The problem is tht only a handful of people make barrels. and they have to get Alexander Arms permission even to do it. And we know how that goes, just look who won the HD battle (SONY BLU RAY) why? because they let everyone else make them, like Samsung, Panasonic etc. But if I really want to punch the same hole all day Ill grab my custom 700 action in 6mmBR. Also the 6.8 is in use right now in the war and doing awesome. It was 1st used as room clearance but now has several long confirmed Sniper kills under it's belt. So if you want a gun that you can, varmint, deer, ground hog hunt, as well as stick beside the bed for home protection, go with the 6.8, as you probably don't wanna grab a 12lb 24" lead sled to clear your house.
Grendelizer
01-05-10, 00:27
Also the 6.8 is in use right now in the war and doing awesome.
Congratulations on your first post, Steve, but, um . . . no.
John
I appreciate your feedback on my first post (here) but to each his own. I have served in the Marine Corps.(2years) National Guard (4 years) NCHP (6yrs) and shot in competition since i was 14 years old, and am now 33. Like I said I have both calibers, along with many, many more. In total I have 46 AR platform weapons, from 22rimfire, to 50BMG. I also hold the 300yd record, with an AR platform rifle. I have been a dealer since age 21, and been building, and manuf. since I was 23. I have my own 100 yd tunnel and a 1000yd outdoor range. Yes the 6.5 is better than the 6.8, but people have been arguing over ballistics forever. I don't even look at them anymore. A 6.5 has better ballistics than a 6mmbr also, but I'll put my 6BR against any AR on the planet. Yes even my Les Bauer. I have over 10 confirmed Sniper shots, and only 1 was a 6.8spc. Also if you dont believe you have to get Mr. Alexander's permission for a 6.5, just ask him, or call Sabre Defense, and they will tell you, how they are able to build them. If theres a factory 6.5 barrel out there, it started w/ Mr. Alexander. I have a cpl posts here, over 1000 at AR15.com, 4-500 at 6mmbr.com, and many else ware.You have the right to your own opinion, but bring your 6.5 to BW here in NC. and we will do a room clearance, scenario or a burglary scenario. Then Ill let you use my 6.8 RRA or my custom built one and check times. There's diff. weapons for diff. reasons, and people will argue all day about theirs. I just had a guy tell me his Rem 700 sendaro would shoot the same hole @ 100 yds so I invited him down to my tunnel and well, it just wasn't his day. Just ask any Military branch how many 6.8's they have in use and how many 6.5's. I'm sure you will see what the proven battle caliber is. (besides the .556) and I've saw 1st hand what a .556 will do to a person @ 427 yds. and it isn't pretty. But like I said people will argue that bullets rise, the 270 is superior to the 30.06, and so on and so on.
Grendelizer
01-06-10, 19:01
Steve, thanks, I think, for your lengthy biography and congrats on your very active shooting and online participation.
My simple point is that I disagree that the 6.8 SPC is currently being used "right now in the war" by military branches. Tested at one point? Sure. "Being used right now," which implies regular issue? Um . . . no. As one small data point, you could check with a long-time poster here, M4Guru, about this. I could be mistaken, but I think he has inside connections with 5th Group and can help separate marketing hype from fact.
John
The OP's point was how did a decision get made to use the caliber chosen.
I chose the 6.8 because it improved on the 5.56, we agree.
I chose using it on the AR platform because of the advantages over a .308 in handling, we agree.
I chose something at least 6 mm because of higher lethality, we agree.
I chose something at least available to buy, not vaporware, we agree.
I chose something many experts, including SF, the AMU, carbine manufacturers, and ammo makers are putting effort into. To the degee the industry is doing that, we agree. But it's about 10 to one 6.8 over 6.5.
I chose a caliber maximized for combat use at combat ranges by combat veterans against other combatants. No agreement, the 6.5 was designed for target shooters by a target shooter. Alexander Arms does not mention a combat intent in the original design at all.
I chose a caliber that works with a 16" barrel from day one, which is what constitutes a carbine. The 6.5 was designed for a rifle barrel from day one, and cutting it down also brings the performance down, too.
Since the 6.5 was designed as long distance target caliber shot from rifles, I have no reason to consider it in a carbine for hunting and home defense.
Asking for each of our reasons and then going the extra mile to refute them is not open minded, it's just beating the drum for the caliber chosen. As I said, admit, and will repeat, the 6.5 is just fine - for long distance shooting. Combat for most participant isn't long distance. Therefore the better caliber is one that fits 95% of what the users experience, not the 5% situations.
I didn't use 3x9 variables on my M16s just because the 5% potential existed that I might need it. I did use a 1Gen Aimpoint on my HK with no magnification, it worked well hunting. Many use newer ones in the service too. Not 3x9's.
Again, the minor need for long distance hits in this conflict is already addressed by the M14. What I wanted was more power for the 95% of shots that will be under 400 yards.
It's what the Germans figured out in WWII, what America went to with the M16, and what many others have gone to - 400 yard cartridges.
Long distance is not the game and hasn't been for 60 years. The average soldier and hunter does not use it or need it. Why chose something not meant for the task at hand?
The OP's point was how did a decision get made to use the caliber chosen.
I chose the 6.8 because it improved on the 5.56, we agree.
I chose using it on the AR platform because of the advantages over a .308 in handling, we agree.
I chose something at least 6 mm because of higher lethality, we agree.
I chose something at least available to buy, not vaporware, we agree.
I chose something many experts, including SF, the AMU, carbine manufacturers, and ammo makers are putting effort into. To the degee the industry is doing that, we agree. But it's about 10 to one 6.8 over 6.5.
I chose a caliber maximized for combat use at combat ranges by combat veterans against other combatants. No agreement, the 6.5 was designed for target shooters by a target shooter. Alexander Arms does not mention a combat intent in the original design at all.
I chose a caliber that works with a 16" barrel from day one, which is what constitutes a carbine. The 6.5 was designed for a rifle barrel from day one, and cutting it down also brings the performance down, too.
Since the 6.5 was designed as long distance target caliber shot from rifles, I have no reason to consider it in a carbine for hunting and home defense.
Asking for each of our reasons and then going the extra mile to refute them is not open minded, it's just beating the drum for the caliber chosen. As I said, admit, and will repeat, the 6.5 is just fine - for long distance shooting. Combat for most participant isn't long distance. Therefore the better caliber is one that fits 95% of what the users experience, not the 5% situations.
I didn't use 3x9 variables on my M16s just because the 5% potential existed that I might need it. I did use a 1Gen Aimpoint on my HK with no magnification, it worked well hunting. Many use newer ones in the service too. Not 3x9's.
Again, the minor need for long distance hits in this conflict is already addressed by the M14. What I wanted was more power for the 95% of shots that will be under 400 yards.
It's what the Germans figured out in WWII, what America went to with the M16, and what many others have gone to - 400 yard cartridges.
Long distance is not the game and hasn't been for 60 years. The average soldier and hunter does not use it or need it. Why chose something not meant for the task at hand?The 6.5 Grendel was NOT designed solely for long distance shooting, it was designed to shoot well at all distances INCLUDING longer distances which it does. It is its lack of problems at all distances that influenced my decision.
Which of the two, or is it three now, 6.8S chambers does your rifle have?
Has there been a determined "optimal" barrel config for the 6.5 Grendel? It looks like the 6.8 is kinda settling on a SPC II chamber with a 1:11 twist and 4-grooves. Personally I just don't shoot beyond 400m, so I'm all for which ever caliber does well at those closer ranges and gets the widest spread adoption.
Has there been a determined "optimal" barrel config for the 6.5 Grendel? It looks like the 6.8 is kinda settling on a SPC II chamber with a 1:11 twist and 4-grooves. Personally I just don't shoot beyond 400m, so I'm all for which ever caliber does well at those closer ranges and gets the widest spread adoption.It would be great for those involved with the 6.8S world if a standard was settled upon, but apparently that has not happened yet. Remington is apparently about to announce a 6.8x43 cartridge which may embody the SPCII chamber, or something different altogether.
The "optimal" barrel for the 6.5G is determined by the use to which you wish to put the rifle, like most calibers out there. My personal rifle has a 16 inch barrel. The good thing about the 6.5G is that there is a standard chamber and always has been.
Well, this thread wasn't to engender a 6.5 vs. 6.8 debate, that's been done several times in other threads.
No, that's simply not true. While I can state categorically that if the 6.5 Grendel did not exist I'd have chosen the 6.8 SPC, however, the 6.5G does exist and is superior in every meaningful way to the 6.8 SPC that I could find, so there was absolutely no reason to make the lesser choice.
On top of that, my long range bolt gun uses 6.5mm bullets, the icing on the cake.
Opinions are like ...well you know the saying.
In every meaningful way huh? Meaningful to one internet personality. Everyone has their reasons, yours are not mine, mine are not "Joe Blows" etc. Your post honestly reeks of the typical internet persona found on another AR Forum, most people come here to AVOID that. If the person who needed to tell you that was me, then so be it.
Lets tone down the cheerleading gents. Both sides. It takes away from the purpose of technical discussion and derails it into nothingness.
Steve, thanks, I think, for your lengthy biography and congrats on your very active shooting and online participation.
My simple point is that I disagree that the 6.8 SPC is currently being used "right now in the war" by military branches. Tested at one point? Sure. "Being used right now," which implies regular issue? Um . . . no. As one small data point, you could check with a long-time poster here, M4Guru, about this. I could be mistaken, but I think he has inside connections with 5th Group and can help separate marketing hype from fact.
John
And some of us know people overseas who might disagree with your point, having spoke to them at Ft. Benning just last month too. Your not in the MIL nor are you overseas, so lets leave the speculation out of tech? Got it? Good. One or both rounds may or may not be used "over there" but this isnt really the place to discuss it.
Gents, this is tech not the internet rumor mill, some of you seem to be forgetting that, least you need a reminder from me. I have really kept out of and above the fray between the 65 v 68, now as the owner of both, albeit one is a bolt gun, I don't think we will disagree, each ctg is improved over the 5.56. Beyond that, there is a precious few of us in here truly qualified to speak about whats being discussed with respect to the MIL.
Yes the 6.8spc is being used right now, I know two people that have been issued them for a fact. One is my good friend in Iraq right now w/ M203 grenade launcher attached. Also one of the longer sniper kills was made in the past w/ a 6.8 spc. I understand alot of people thought they just tested them, but how did and are they testing them? By issuing them of course. We are also using the 6.8 at BW, and so are the DEA in a few states. But my point is it is being used, and Prvt. Adam Bass is carrying one right now in Iraq. Trust me my father retired 2 months ago from the Marksmanship unit from Fort B. They will also tell you that they only shoot FMJ's in battle, but just ask some of the Marksmen what their friends are sendin them in the mail, (not fruit cakes) hp's and Ballistic tips. Woops, the cat's outta the bag now. lol
Thanks Cold your exactly right, I would bet $ that some of the people posting here don't even own a 6.8 or 6.5. they just read the net, and think it's the Gospel. It's the same as real life, people lie in person, on the phone and yep on the internet. Both cartridges are better suited than the .556, but so is the .243, 260, 6mmAR, Turbo, and the new 30 RAR, (which I just bought) but haven't yet fired a round through it. I could brag about the ballistics, but that's just BS. It's how it fires in the field, and on paper, and on the enemy that counts. I know of a co. that's in the process of making a cart. right now that is supposed to blow the Mighty Grendel away. I also just built a 20 practical on a Noveske lower that shoots unreal @ 100m and destroys ground hogs at 400yds. And odds are there's many more being built for the AR right now. I was a Bolt man only! until I purchased my 1st RRA Varmint A4, and now my buds say I'm cheatin when we shoot p dogs in Montana, against their 40x's, and custom single shot bolt guns.
Hey fastpat? how many of those 6.5 bullets (or icing on the cake) have a win at any IBRA shoot? Id say the count is very low since the 6mmbr holds more records than any other cart. Also when you start thinkin you have the best caliber in an AR platform around, just go shoot a 6mmAR or the new Turbo, both will set the Grendel in it's place. And I talked to Bill Alexander, and yes the 6.5 was made to be a target gun, and he also said that due to gasses he would pass up on a 16" upper, quote "Like building a Keith Black Hemi Drag racing motor, and putting 87 octane, and a 1 inch pipe with a muffler on it". He also said the problems he has seen were all on the 16" versions. But now do I love my Sabre 24" Grendel? Yep, sure do. But at 13lbs, I doubt it's the gun I'll reach for if ever broken in on, matter of fact it would probably be my 18" 12ga pump, or my Glock 27 on the night stand. Every gun has it's purpose, as well as every caliber. Just call Bill yourself, or Sabre Defense, they will tell you what the guns were built for. (Paper, Varmints) And like Cold said lets just chill and say what we know about the caliber, Everyone knows that the car, gun, or whatever you own, is the best at the time, and people who brag alot about it are probably just wanting the opposite caliber.
Yes the 6.8spc is being used right now, I know two people that have been issued them for a fact. One is my good friend in Iraq right now w/ M203 grenade launcher attached. Also one of the longer sniper kills was made in the past w/ a 6.8 spc. I understand alot of people thought they just tested them, but how did and are they testing them? By issuing them of course. We are also using the 6.8 at BW, and so are the DEA in a few states. But my point is it is being used, and Prvt. Adam Bass is carrying one right now in Iraq. Trust me my father retired 2 months ago from the Marksmanship unit from Fort B. They will also tell you that they only shoot FMJ's in battle, but just ask some of the Marksmen what their friends are sendin them in the mail, (not fruit cakes) hp's and Ballistic tips. Woops, the cat's outta the bag now. lolCome back to us when the contract is let for a Corp or Brigade level purchase. Special Ops guys get to use lots of different, not mil-spec weapons, that's not an earth shaking revelation. The standard issue ammo fired by designated markesmen using M14's are match hollow points (lots of Lake City stuff), it's a myth that they're prohibited for use by the military. They are not.
Thanks Cold your exactly right, I would bet $ that some of the people posting here don't even own a 6.8 or 6.5. they just read the net, and think it's the Gospel. It's the same as real life, people lie in person, on the phone and yep on the internet. Both cartridges are better suited than the .556, but so is the .243, 260, 6mmAR, Turbo, and the new 30 RAR, (which I just bought) but haven't yet fired a round through it. I could brag about the ballistics, but that's just BS. It's how it fires in the field, and on paper, and on the enemy that counts. I know of a co. that's in the process of making a cart. right now that is supposed to blow the Mighty Grendel away. I also just built a 20 practical on a Noveske lower that shoots unreal @ 100m and destroys ground hogs at 400yds. And odds are there's many more being built for the AR right now. I was a Bolt man only! until I purchased my 1st RRA Varmint A4, and now my buds say I'm cheatin when we shoot p dogs in Montana, against their 40x's, and custom single shot bolt guns.Yeah, I used to shoot gophers in Montana with my 257 Roberts, lots of fun, let's see, when was that? Maybe 1970-71 or thereabouts, you remember how it was then, dontcha? It's difficult to hit a target at 200+ yards when they're only 7 inches tall and you're layin' down on a big flat rock, using a blanket as a rest.
Hey fastpat? how many of those 6.5 bullets (or icing on the cake) have a win at any IBRA shoot? Id say the count is very low since the 6mmbr holds more records than any other cart. Also when you start thinkin you have the best caliber in an AR platform around, just go shoot a 6mmAR or the new Turbo, both will set the Grendel in it's place. And I talked to Bill Alexander, and yes the 6.5 was made to be a target gun, and he also said that due to gasses he would pass up on a 16" upper, quote "Like building a Keith Black Hemi Drag racing motor, and putting 87 octane, and a 1 inch pipe with a muffler on it". He also said the problems he has seen were all on the 16" versions. But now do I love my Sabre 24" Grendel? Yep, sure do. But at 13lbs, I doubt it's the gun I'll reach for if ever broken in on, matter of fact it would probably be my 18" 12ga pump, or my Glock 27 on the night stand. Every gun has it's purpose, as well as every caliber. Just call Bill yourself, or Sabre Defense, they will tell you what the guns were built for. (Paper, Varmints) And like Cold said lets just chill and say what we know about the caliber, Everyone knows that the car, gun, or whatever you own, is the best at the time, and people who brag alot about it are probably just wanting the opposite caliber.What the 6mmbr will do isn't particularly relevant in the AR world, I chose my AR rifle caliber on the basis of its capabilities, development, standardization, efficiency, and so on.
Now, let's get back to tech.
How about those two angle throats?
Opinions are like ...well you know the saying.
In every meaningful way huh? Meaningful to one internet personality. Everyone has their reasons, yours are not mine, mine are not "Joe Blows" etc. Your post honestly reeks of the typical internet persona found on another AR Forum, most people come here to AVOID that. If the person who needed to tell you that was me, then so be it.
Lets tone down the cheerleading gents. Both sides. It takes away from the purpose of technical discussion and derails it into nothingness.
+1.
Honestly, it's just a caliber. Darned if 6.5 was issue, we'd be arguing the next bigger size.
As a technical note, the 6.8 has had some evolution. There are some reasons beyond the control of the innovators, but there does seem to be a correction - and that's taken care of with .100 leade throats. Now the handloaders and ammo designers have moved to the next level.
Exciting times as innovation in America is still alive and well.
+1.
Exciting times as innovation in America is still alive and well.
Agreed, and we all benefit from it. At times "we as shooters" are our own worst enemey, and these online forums (and stupid tirades) prove it.
Bill Alexander
01-08-10, 21:43
Hey fastpat? how many of those 6.5 bullets (or icing on the cake) have a win at any IBRA shoot? Id say the count is very low since the 6mmbr holds more records than any other cart. Also when you start thinkin you have the best caliber in an AR platform around, just go shoot a 6mmAR or the new Turbo, both will set the Grendel in it's place. And I talked to Bill Alexander, and yes the 6.5 was made to be a target gun, and he also said that due to gasses he would pass up on a 16" upper, quote "Like building a Keith Black Hemi Drag racing motor, and putting 87 octane, and a 1 inch pipe with a muffler on it". He also said the problems he has seen were all on the 16" versions. But now do I love my Sabre 24" Grendel? Yep, sure do. But at 13lbs, I doubt it's the gun I'll reach for if ever broken in on, matter of fact it would probably be my 18" 12ga pump, or my Glock 27 on the night stand. Every gun has it's purpose, as well as every caliber. Just call Bill yourself, or Sabre Defense, they will tell you what the guns were built for. (Paper, Varmints) And like Cold said lets just chill and say what we know about the caliber, Everyone knows that the car, gun, or whatever you own, is the best at the time, and people who brag alot about it are probably just wanting the opposite caliber.
While I talk to many customers during a week I very much doubt that I would even have the context to quote regarding a "Keith Black" drag motor. My knowledge of drag racing is virtually non existent conversely my memory for a conversation such as this is fairly unfailing. My problem therefore is that in the absence of talking to this gentleman, one wonders as to the credence of not only this but all the other information laid at the gates of this forum
In the first instance the Grendel was not designed as a target gun, nor would I represent its design heritage as being intended for target work. If the conversation was related to a whitetail cartridge especially for those states to the West were the range begins to get longer then this is where I would begin. 6.5 was not selected for its ability to punch paper but for its ability to punch venison. That it has a flexibility for other tasks is beneficial.
Turning to "gasses" I am yet again at a quandary as to the existence of this conversation. I manufacture the 16" upper unit and have the design authority to produce it in whatever format best suits the application. Sure in the context of an esoterically long range weapon where one can contemplate the exact gas balance for minimum carrier velocity, then the 16" Grendel runs a bit hard, but is itself very well suited to use as a utility gun which may be required to work in less than ideal conditions.
I think it might be best if those who wish to ask do indeed contact me. I place little credence in whose using what as an argument to select a rifle caliber and have no time to discuss such matters on an open public forum.
Bill Alexander
well fmjs were all we could use when i was in the mil. so thats what i base it on. sooo, obviously bill doesnt remember, the convo. athink ai have it on email and will post. sure it will kill a deer, so will my kids chipmunk 22lr, and has. doesnt say much, Still ask Rem, Fed, WIN. HOW MANY 6.5 THEY MAKE PER YR. anywhoo, i thought we all got the point, and obv the 6.5 doesnt', produce as much gas as the reg. m4 .556, and they admit having gas issues on the 16". and if i owned the co, id say it was built for everything too. All about the benjamins, and we all know that. Why I like companies that offer diff. cals, they just say " get what suits you best.
In the first instance the Grendel was not designed as a target gun, nor would I represent its design heritage as being intended for target work.
Quote, Bill Alexander.
Thank you for taking time away from your job to address this issue. Unfortunately many of us researching and examining the prospect of what this cartridge does have been misinformed by many sources as to the origins of the cartridge - which was designed by others long before they met you to market it.
I look forward to seeing your website corrected to amend the misinformation.
PS Sorry you missed out on the whole drag racing thing having grown up in England. Keith Black is well known in America as an expert on large displace Dodge Hemi engines producing 2000 hp. Obviously, management of the engine as an air pump, ie. "gas," is of paramount importance.
I think this topic has run its course.
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