Shot counters

[tirod]

There is existing tech to count rounds fired: http://www.thefirearmblog.com/blog/2011/04/06/beretta-a400-xplor-action/#comment-59604

It can either be a thin film pressure transducer, or an automotive knock sensor. The first were designed for scales and have been around for decades, the second was installed in cars since the late eighties to sense excessive advance timing for the conditions and allows the ignition to retard, avoiding engine damage.

Just count the pings, we're dealing with more pressure than a motor ever sees.

Since it is old tech, can and now has been done, there's little reason not to expect the Beretta ARX 160 to show up at the Improved Carbine trials without it. That and a suppressor mount puts it ahead of anything Colt or FN has made publicly known (to me.)

The quick change barrel won't be compromised, use spring loaded door jamb contacts - most new cars have them.

It's not like the 1911 replacement before the internet, a lot of people out of the loop were complacent and completely surprised. No guarantee anything will change, but - at least you have some heads up of the potential.

Beretta ARX. It could happen, it is a fielded gun, in larger quantities than the SCAR.

FYI, don't be that (old) guy. Things change.

[Hmac]

Does the non-military version come with an MP3 player built in too?

[ZRH]

Yeah but why? Like an odometer? The point of a rifle is to go bang when you pull the trigger.

Don't really know why you compare it to the 1911 except the beretta/colt thing. The Army was looking for a 9mm handgun, the Beretta worked and it was cheap[er] than the competition.

[87GN]

Yeah but why? Like an odometer? The point of a rifle is to go bang when you pull the trigger.

Knowing exactly when to replace Parts #17, 38, and 22a of the 500,000+ rifles in service would be beneficial.

Otherwise, the rifle stops "going bang when you pull the trigger."

[QuietShootr]

Somebody needs to design one into a MIAD grip core. Add a USB port on the inside, and voila! maintenance intervals are simple, and could be tracked with software.

[Hmac]

Seems like it would be easy enough to design an insert for your grip or stock, size of a CR123 or AA battery, that would be a nice little shot counter. I don't see why it would have to be permanently built into the rifle.

[An Undocumented Worker]

Combining the Shot Timer with Load pressure gauge would provide enough data to reliably determine when a part is reaching the end of it's life, and would be really usefull when making reloads.

the pressure gauge would have to be made into or have a barrel made for it. If not. it would have to be calibrated after installation.

[Suwannee Tim]

If I were building a round counter I would use an accelerometer on silicon to detect the shots. This technology is two decades old, very mature and reliable. It might count hard drops as shots which should not be any big deal, provided the rifle was not dropped hard thousands of times. It could store a complete maintenance history in memory, a useful thing. It could also incorporate a little generator that extracted a bit of energy from each shot to run the electronics and charge the battery, similar in concept to a self winding watch but moving a magnet through a coil instead of winding a spring. This is absolutely doable and no big challenge. Except for the little generator, this could be done by an EE student as a Senior Project using commercial off the shelf parts. The little generator would make a good project for an ME student.

Seems like it would be easy enough to design an insert for your grip or stock, size of a CR123 or AA battery, that would be a nice little shot counter. I don't see why it would have to be permanently built into the rifle.

It could and should be a little module that inserts into the grip or some other convenient recess.

[ZRH]

Knowing exactly when to replace Parts #17, 38, and 22a of the 500,000+ rifles in service would be beneficial.

Otherwise, the rifle stops "going bang when you pull the trigger."
Well you cant adjust powder mixture (is in separate case) or delay the ignition of a round (would be dumb) so essentially you have a odometer that just counts rounds... You could just put an accelerometer (iPhone) in the grip and achieve the same effect.

[Hmac]

Military started looking at piezoelectric round counters back in 1977. The patent for the devices was filed in 1975.

http://www.freepatentsonline.com/4001961.html

[Iraqgunz]

The has been one of the stupidest ideas to hit the scene in years. I can see the military adopting it though since they love to spend money on shit that serves no purpose. Like the "improved Picatinney" magazines, ACU's, the wheel, etc...

This is the same military that can't seem to fathom that aluminum magazines are diposable. On that note I don't understand why they don't purchase new springs and followers to refurbish magazines. i could go on and on......

[Suwannee Tim]

Many firearms parts fail due to material fatigue. These failures can be prevented by a program of planned replacement. It requires a knowledge of maintenance history and a round count.

Suwannee Tim
Mechanical Engineer
Four plus decades experience with machines of many types

[Iraqgunz]

I don't know how round count can factor into when there is no baseline knowledge. Some barrels have worn out faster than others, bolts cracked when others didn't, etc...

How are you going to say that a spring will wear in xxxx amount of rounds? Too many variables. But, some common sense stuff can be replaced/

Many firearms parts fail due to material fatigue. These failures can be prevented by a program of planned replacement. It requires a knowledge of maintenance history and a round count.

Suwannee Tim
Mechanical Engineer
Four plus decades experience with machines of many types

[MistWolf]

"Bushmaster M4gery For Sale. Only 213 original rounds! No crappy Wolf fired in this baby! Comes with 2 C-Mags, 787 rounds of Golden Tiger, RDS sight, bipod, HID "Angel Eyes" lighting, leather upholstered VFG, full instrumentation, tinted windows, mag rims, Pioneer stereo w/subs. Gets great gas mileage! Serious inquiries only"

[ZRH]

Many firearms parts fail due to material fatigue. These failures can be prevented by a program of planned replacement. It requires a knowledge of maintenance history and a round count.

Suwannee Tim
Mechanical Engineer
Four plus decades experience with machines of many types
What about heat, corrosion... The first thing you ever learn about fatigue is that it's pretty random statistically.

Either way, round count is a factor, but it's way down the list. Automatic fire can eat a barrel while you watch it. Having a hmmwv run over all your gear isn't going to come up on the round count and so on. That means the rifles have to be visually inspected for maintenance, stuff is going to be replaced per PM procedures already in place.

Putting something on a rifle that doesn't significantly enhance it's primary function is just dumb.

[Ned Christiansen]

A couple years ago I talked with a guy that said he was developing a round counter. As I recall it would allow the downloading of recent history so that a timeline could be created, showing when rounds were fired, how many, and at what rate, to include auto.

ETA: this got me thinking so I googled the thing:
http://www.leitner-wise.com/countashot.html

[SGTMAJ]

Ned I think I saw examples of that from the Sig LE/MIL rep 2 years ago at SHOT. I also have seen examples from Colt and Beretta both being molded into the grip and external. Some were kinda cool as to the fact when ever the weapon leaves the armory and passes through the door the sensors pick up when it left when it returned for accountability purposes. It also shows what happened in between how many shots fired how fast they were shot. Some even had it down to the point where certain rounds had unique shock profiles so they know what grain bullet was fired. all this was looking at future weapons solicitations for the military

[QuietShootr]

I don't know how round count can factor into when there is no baseline knowledge. Some barrels have worn out faster than others, bolts cracked when others didn't, etc...

How are you going to say that a spring will wear in xxxx amount of rounds? Too many variables. But, some common sense stuff can be replaced/

Well, I think there IS enough baseline knowledge to be able to say, "OK, the average bolt fails at 12,000 rounds, so we'll make the replacement interval 8,500 rounds." or "M4 recoil springs are usually shortened past the reject length at 15,000 rounds, so when the weapon hits 15k, it gets a new buffer spring" then when the weapon gets checked back in and scanned, they get a warning that it's time to replace the bolt (or whatever). What's wrong with that?

[Suwannee Tim]

What about heat, corrosion... The first thing you ever learn about fatigue is that it's pretty random statistically.....

It's not random it's stochastic. Planned replacement of parts subject to fatigue failure is a practice almost as old as aviation which is where is was first applied on a large scale. It is a very powerful technique for preventing failure. To do it you have to have some measure of lifetime, flight hours for example, or round count.

Well, I think there IS enough baseline knowledge to be able to say, "OK, the average bolt fails at 12,000 rounds, so we'll make the replacement interval 8,500 rounds." or "M4 recoil springs are usually shortened past the reject length at 15,000 rounds, so when the weapon hits 15k, it gets a new buffer spring" then when the weapon gets checked back in and scanned, they get a warning that it's time to replace the bolt (or whatever). What's wrong with that?

Which is exactly how it would be done. But you have to have a maintenance history and a round count.

[Iraqgunz]

I still don't find it feasible. What if the weapon gets dropped into water and the shot counter goes tits up? Do you overhaul the weapon just because?

I think that the last thing we need to stick on a weapon is something that's gimmicky and hasn't been proven.

Well, I think there IS enough baseline knowledge to be able to say, "OK, the average bolt fails at 12,000 rounds, so we'll make the replacement interval 8,500 rounds." or "M4 recoil springs are usually shortened past the reject length at 15,000 rounds, so when the weapon hits 15k, it gets a new buffer spring" then when the weapon gets checked back in and scanned, they get a warning that it's time to replace the bolt (or whatever). What's wrong with that?

[QuietShootr]

I still don't find it feasible. What if the weapon gets dropped into water and the shot counter goes tits up? Do you overhaul the weapon just because?

I think that the last thing we need to stick on a weapon is something that's gimmicky and hasn't been proven.

I agree, but I think it could be a completely sealed unit. And if it did fail, it wouldn't matter a bit to the functionality of the weapon. And the software I'm envisioning would have a record of everything that happened up until the last time the weapon was checked out, so you could easily pair a new module to the weapon and have minimal data loss. Make an SOP that a malfunctioning data unit is considered to add 500 rounds to the round count on the gun, or something like that.

For fleets of weapons, this would be a valuable predictive maintenance tool. I'm picturing that any time work is done to the weapon, the module is scanned so that the maintenance system shows the entire history of that particular weapon. Require that any changes made be entered in the weapon's permanent record, and you're golden.

[MarshallDodge]

I still don't find it feasible. What if the weapon gets dropped into water and the shot counter goes tits up? Do you overhaul the weapon just because?

I think that the last thing we need to stick on a weapon is something that's gimmicky and hasn't been proven. I am not going to question whether or not something like this is really needed but it could easily be built to withstand the rigorous conditions that a firearm has to withstand.

I am thinking a small tubular device around a 1/4" in diameter and 1" long that could be molded into a handguard, stock, etc. It could be self powered (think kinetic watches or those flashlights that you shake) and readable through an RFID or similar interface.

If Magpul came out with something like this tomorrow 90% of the AR community would buy one. :cool:

[Ned Christiansen]

Gunz, you stick-in-the-mud!:p

Do you not look forward to the day when, like your car, your rifle will have lights that come on and say things like, "CHECK BOLT", or, "CHANGE GAS RINGS"?

[Whiskey_Bravo]

I didn't see it posted, but LaRue has one available.

http://stores.homestead.com/Laruetactical/Detail.bok?no=456


21st Century Weapons Monitoring

Countashot is a new, incrementally variable electronic data capture system that records, stores and displays real-time read-out of each shot discharged by a firearm, allowing the operator to instantly know how many rounds they have fired, when the firearm requires reloading, the lifetime usage of the firearm and the precise time of each shot to 100th/second.

Countashot has a memory capacity of 400,000 events and is capable of distinguishing between dry-firing, rough-handling and actual ammunition discharge using its patent pending technology.

The data stored can be downloaded for analysis to a personal computer. Two way communication between the operator and Countashot allows the system to be upgraded for support to additional data retrieval functions and customization to the users specification.

Countashot automatically resets itself to the default round capacity preset by the weapon's operator and can be mounted on any existing firearm regardless of caliber.

[Hmac]

Must be a product whose time has come...

http://www.m4carbine.net/showthread.php?t=78497


http://i1010.photobucket.com/albums/af230/weaponsrelated/roundcounter.jpg

[Suwannee Tim]

I still don't find it feasible. What if the weapon gets dropped into water and the shot counter goes tits up? Do you overhaul the weapon just because?

I think that the last thing we need to stick on a weapon is something that's gimmicky and hasn't been proven.

It could be made very rugged and hard and resistant to any survivable environmental condition. This silicon LSI is the same technology used to make fuzes for artillery and mortars. It will be a gimmick until it is proven in service which may take some time or not depending on how large the design committee is. Small arms are the last of the soldier, sailor and Marine's equipment not to be maintained on a planned basis. With my limited background and knowledge of this sort of thing I don't think breakage of small arms due to fatigue is a big problem in the field or this solution would have already been implemented. It was a big problem in aviation and was killing people and planned maintenance was pretty quickly adopted. I helped overhaul the engines of a B17 of the Confederate Air Force, the intake and exhaust valves were due for planned replacement. I was being trained to use the Magnaflux machine and examined some valves and sure as hell found fatigue cracks. I put several of the valves in a vise and with a few hard whacks was able to break them off and expose the small but growing cracks for examination. These cracks would eventually have grown then caused complete failure of the valve and serious damage to the engine. In a single engine aircraft it could well result in the loss of the aircraft and occupants. Fatigue is a very real thing which can be anticipated and mitigated.

[ZRH]

It's not random it's stochastic. Planned replacement of parts subject to fatigue failure is a practice almost as old as aviation which is where is was first applied on a large scale. It is a very powerful technique for preventing failure. To do it you have to have some measure of lifetime, flight hours for example, or round count.

Which is exactly how it would be done. But you have to have a maintenance history and a round count.
Stochastic as in a non deterministic process as in more random as time goes by. I addressed the rest of it in the part you cut out. Rate of fire (500 rounds auto will make a barrel sag under it's own weight) and end use are much larger factors in rifles than round counts. They get almost daily visual inspections in the field and each time they shipped back from theatre, failure to actually address maintenance issues is a unit/institutional interia thing, not a "we don't have a round counter" thing. The sheer number of people still being trained to run their weapons dry is insane.

[Suwannee Tim]

....Rate of fire (500 rounds auto will make a barrel sag under it's own weight) and end use are much larger factors in rifles than round counts.....

A barrel that sags under it's own weight did not fail due to fatigue. My best SWAG is the fatigue life of bolts and springs would be determined almost exclusively by round count. Rate of fire would be irrelevant and temperature would have little effect. Taking other factors like temperature into account would complicate the problem and increase costs far beyond any possible value. The use of a round counter is not to provide for planned replacement of things like barrels that can be readily inspected and gauged. A round counter is useful for preemptive replacement of parts subject to fatigue failure. Fatigue is difficult to impossible to detect with the naked eye or simple tools like magnifiers. It may be detectable by methods such as MPI. MPI is very sensative to the complexity of the part with more complex parts being more difficult to inspect. An exhaust valve for example is a good candidate for MPI, it has mostly smooth curves and few sharp edges and when it cracks the cracks will be perpendicular to, not parallel to the edges. MPI is a labor intensive, expensive process with significant limitations. An AR bolt by contrast is very complex with lots of inside corners which bend the magnetic flux and obscure the growing cracks. From the photos I have seen the cracks that occur in AR bolts run parallel to the inside corners of the bolt lugs. These cracks would have to be pretty large before they would stand out from the inside corner. There are three choices far parts subject to fatigue failure, run to failure, planned replacement and expensive, possibly ineffective inspection.