M4 questions
One of my SSG is going to purchase a M4 chambered in 5.56/223 when return home. Our question is this: What are some of the major advantages/disadvantages of piston operated v/s gas operated? From what I have read, I understand that the gas operated is somewhat less reliable that the piston operated. However, if the gas operated M4 is well maintained oiled and broke in properly it is truly a fine weapon. Is there much of a difference in accuracy, bullet velocity, or recoil when comparing the two?
Also, what some of the better manufactures of both. Currently we both have Colt, however we are aware there are many others. That being said which would ones would be considered top quality?
Also, what some of the better manufactures of both. Currently we both have Colt, however we are aware there are many others. That being said which would ones would be considered top quality?
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quote:Is there much of a difference in accuracy, bullet velocity, or recoil when comparing the two?
The recoil is slightly different, but still not worth adding to the equation. Accuracy and bullet velocity are the same, manufacturers are still using the same barrels they do in their gas systems upper receivers.
As far as gas piston manufacturers in AR15's you have; LWRC, POF, LMT, Ruger just came out with one, but they FUBAR anything they try to make the first time around so I would pass on that. You also have several different conversion kits. Along with non AR15 guns.
As far as advantages/disadvantages. Piston guns are more expensive then gas operated guns. There are more mechanical parts. With the AR15 gas operated guns, there is a bolt lean issue, and the bolt drags on the bottom of the bolt. Piston guns run a heck of a lot cleaner and are easier to clean.
If I was looking at a piston gun, I think I would look at a different platform. Either a Sig556 or HK gun, that is just me though.0 -
Due to parts availability, those proprietary designs are also much less likely to remain functional in the really long run.
The AR is like the small block Chevy of firearms. Everyone and their brother makes parts/accessories for them.0 -
Shoff has it.
There is no practical difference in accuracy, weight, recoil, or muzzle velocity.
There probably is a subtle difference in the character of the recoil, but come on. . .this is a .223 we're talking about. There is barely any recoil anyway.
The main advantage of the piston design is reliability. The ordinary M4/AR-15 design vents carbon-laden gas into the gun action (described by some as "pooping where you eat").
The piston design avoids that, keeping the action cleaner. The design in general *may* be less ammo sensitive, though that depends on the exact execution.
But even the pistol design guns aren't entirely maintenance free, and the other usual problems with well-used AR-15 guns can still arise (ie magazine and extractor wear, etc).0 -
If you want piston driven, get something originally designed for it as opposed on an after-thought bolt on.
There is a SAR4800 in 223 (FAL, takes AR mags) for sale on falfiles.com, and of course there are others like the Daewoo. New production there is the ATR-1, again FAL design. Or the HK, SIG, etc.0 -
I get about 3400 FPS out of my 16" rifle with hot 45 grain loads, About 3600 out of my rifle.
Recoil is sharper with an M-4 Or CAR style carbine that has collapsable stock buffer and CAR(7") length gas tube.
But nothing to whine about, the cycleing is more violent during shooting with a car length gas system, The gas tap hole in the barrel is right where the propellant gasses have reached the highest point in the pressure curve. This results in violent cycleing with both piston and direct impingement guns. (the AA 1 piece bolt, described below adresses this with piston carbines)If you really want an M4 just buy a Stag arms and mod it how ever you want. It will save you some dough.
A mid length gas system runs alot smoother. Armalite and CMMG both make good mid length carbines, maybe a few other companies do as well. The mid length gas system would be my choice if I wanted a traditional DI carbine.
Alot of the piston systems will cause the carrier to cant or the replacement gas key can break. get a one piece carrier that has a block machined where the gas key is on a traditional carrier. it catches the piston, and reduces the likelyhood of breakage. As far as I know LMT and Adams arms are the only two companies that make them.
I'd advise going with an Adams piston kit and 1 piece bolt carrier.
The Adams 1 piece bolt carrier group adresses the carrier tilt and carrier key breakage problems that have been expirianced with the older designs. The "key" is machined into the bolt carrier. The bolt is spring loaded so that it unlocks more slowly, so that the cycleing isnt so violent.
the Adams carrier will work with a cmmg or bushmaster piston kits If one of those seem mechanically more sound.
Adams arms states that it is supposed to work with all piston kits, but I cant say one way or the other, The CMMG and BM are the only two kits I know for sure they work with from personal expiriance.
Edit.
Sorry for the slop I was preoccupied and trying to type at the same time. I hope this may be more clear. Sorry again.
LMt makes a piston uppers and complete rifles, but it will cost you 1,200.00+ just for the upper.0
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