03-10-2011, 07:58 AM
There was a lengthy post about the subject by another member (I forget who?) on the old forum. The underlying theory (as best I recall) had to do with reciprocating mass. A DI gun has all of the reciprocating mass (bolt, bolt carrier, buffer, action spring, etc) traveling in direct line with the bore axis, whereas piston guns have at least a significant portion of their reciprocating mass above the bore axis. This will cause additional off axis "upset" during the time the weapon is cycling. If you watch slow motion videos of some weapon systems you can actually see the torque and vibration that this causes. A slow motion of the AK looks like a train wreck on some of them. You can actually see lots of receiver flex and other stuff going on. How much this actually applies to the AR platform I have no idea, but I haven't seen any match guys running to the piston system for their match guns. It could be that the whole issue is overblown, but maybe not also. If Bill A. (or others) can turn out accurate piston guns, then people will probably ease up on this prejudice.