Now you have done it. The mere mention of LWRCI sends Markm over the edge.
I have 3 piston guns in my stable - REPR, M6A2, and LMT MRP. All three are just as reliable as my other DI weapons.
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Using a suppressor on a gas gun is often cited as a cause for increased bolt speed (force) which can only come from increased gas tube pressure on a gas gun, no?
Use of a can lengthens the amount of time higher than ambient pressure remains in the barrel (and hence, gas tube) so it seems reasonable to say that the source of dirty overall is both from the barrel/chamber and gas tube. Obviously, the barrel will accomodate a lot more gas than the tube will in this environment and is connected directly to the chamber so maybe the amount from the tube can be considered negligible?
I guess my pipe dream of pistons being great for cans is busted. :suicide:
Hey OP, you don't expect to get many real answers do you?
Yes:
HK...cracked upper receivers when shot hard suppressed. Firing pin safety failures. Broken bolts.
POF...highly worn receiver extensions which caused erratic bolt velocity which was causing failure to eject, failure to feed etc whenever the bolt carrier would get caught in the trough cause by carrier tilt. Cracked bolt, cracked log at top of bolt. Large amount of finish wear/gouging caused by front-top of bolt carrier dragging along the receiver bore as the carrier tilt. A temp fix is a new receiver extension and new upper receiver (two things that don't really wear out in DI guns by the way). One particular POF I've seen will not run on this one particular AR lower but on that same AR lower all DI uppers (7 different ones) worked just fine. Corrosive pitting of the gas piston and op rod. Broken bolt lug which got between the carrier and upper receiver and ruined the upper receiver which required a new receiver and new bolt.
early ARES....bent op rod in less than 600 rounds on full auto on a 11.5" upper, due to spigot coming lose after the gas tube roll pin 'exited stage left'.
LWRC...I've thus far fixed 4 lose barrel nuts, replaced heavy worn receiver extensions with this wear causing unusual stoppages (fixed with a new extension and anti-tilt buffer). Early ones had carrier keys coming lose before they key was integral to the carrier. On two early one I replaced two broken bolts (before Matech).
PWS...lose gas block (2nd gen after moving away from a pinned gas block to a set screw gas block). Newer pinned Diablo style is much better. 1st gen I had the piston (which is attached to the carrier) came lose but I caught it before it caused stoppages.
LMT...highly worn receiver extensions from carrier tilt causing unusual stoppages fixed with a new receiver extension and anti-tilt buffer. Lose barrels if not checked regularly.
So to summarize what I've said in the past, If Eugene Stoner wanted the AR to be a 'gas piston' design he would have made it that way from the get go. Trying to make the AR15 platform a piston gun is like Chevrolet back in the day trying to make a good diesel engine out of the small block 350 (5.7L) engines ...it didn't turn out to well.
Well said. Did the PWS experience less problems and parts breakage due to the fact it is a long stroke piston op and probably has a lower BCG velocity? Or is this an incorrect assumption?
I bought a CMMG piston gun (gen 1) during the Obamamania rush when people, including me, were buying everything with a trigger. It was NIB of course.
Somewhere between the 10th and 20th shots of Federal XM193 ammo, the action locked up tight. TIGHT!! So I sent it back to CMMG. It was there a month or so and they sent it back as a Gen 2 gun. I could see that some parts were different while some, like the barrel, were the same. They did not charge for the repair. The gun did not come back with a work order that said what was wrong.
At that point I was spooked and sold the gun for a big loss. The new owner said he really liked it so maybe Gen 2 was the magic that it needed.
Robb has also shot and evaluated the Ruger piston AR, which experienced a great deal of carrier tilt and associated wear in the first 1,000 rds.