[MHGinTN]

"Personally I don't want a piston driven rifle." Oh I know, all those Ak 47s and Ak 74s, they are just so riddled with problems, can't rely on them to run when you need them ... (/sarcasm)

I have no idea what problems you imagine are inherent in piston driven ARs, but I have built several and have found two that run flawlessly, the Osprey Defense and then the Adams Arms. I prefer the Osprey because it is so trouble free. But the dialability for pressure of the Adams Arms version is good, too. I would guess that around 10 to 20 thousand rounds I may need to replace the drive rod ont he Osprey, but running cool in the bolt and such attributes makes it well worth it.

[Durus]

The oft paised rip off of the Sturmgewehr 44 is reliable and that is about all you can say about it.

The problems with a piston are accuracy, additional reciprocating mass, and at least in the AR, additional wear in the receiver. No piston AR can touch the GI AR in accuracy, and that alone is enough reason to ditch the concept IMO.