Gold & Silver Forum - AR15~Piston vs. DI

In firearms designed to use the piston it works great, guns like the AR 180, Galil, AK47, etc it does not cause a problem. But the AR 15 was not designed to function with a gas piston and by changing just this one part does cause bolt carrier tilt. Even the best made suffer from this as the piston causes an off center impulse on the BCG.

Quote:

DefenseReview received the following post-interview via email from John Noveske: "Also, we should mention the poor choice of platform for the piston conversion on a round receiver bore as found on the M16/M4 system. All other piston type systems out there utilize a railed receiver design, like the M14, AK-47, M249, FAL and so on. The round receiver bore design used on the M4 is only acceptable for the standard op system. The carrier and bolt expand on axis with the bore under the normal gas impingement cycle, but on a piston gun, you run into off center impulse issues with carrier tilt and incorrectly designed carrier contact points. Some designs attempt to address the carrier tilt problem with over sized carrier tails and rollers. I do not believe the receiver extension should be used in this manor. I know many people are very happy with their piston weapons. This is not meant as a knock on the piston conversion systems out there, but as a philosophical dialogue focused the new physiological relationships applied to the M16/M4 platform through the introduction of an operating system which has traditionally been applied to receivers with rails for the bolt and/or carrier. I would rather see an entirely new weapon system designed for the piston from the ground up. I believe there several outfits currently working on this."

Without a rail system for the BCG to ride on or a way to center the piston strike in the mass of the bolt I don't see a way to fix this. Even the Seals dumped the idea and went back to direct gas impingement. With the exception of 10 inch suppressed full auto rifles no one has been able to show the piston has any advantage over the DGI system which the rifle was designed to function with. I just don't see a reason to take something that works very well and try to make it into something that won't work any better. I could probably adapt a Chevy 350 head to a Dodge 360 block but would it be an improvement?