9mm Piston Driven AR, Can it be done?

[sasquatch981]

Just curious, if anyone has ever tried to to use an aftermarket piston driven system like adam arms, osprey defense, etc on a 9mm AR build.  Now before you go an say "the 9mm AR is a blowback design", I know that.  I am thinking outside the box here.  Trying to lighten the carrier, and all the reciprocating weight.  Afterall the Sig MPX is a piston 9mm, and the recoil is alot less than a typical 9mm AR.  Just curious as to what you other tinkerers may think.

[MikeRush]

A number of people are making direct impingement 9mm uppers at this point. Most need a bit of extra gas to cycle.

 

I think the issue you would have with a piston in a 9mm AR is the barrel nut. The MPX taps its gas from essentially where the barrel nut is in relation to the chamber on an AR.

 

There are a few people running skeletonized 9mm DI bolts and lightweight buffer setups that are claiming proper function with factory ammo. If you were able to use a similar setup with a piston you may be able to get it to run.

 

I really want someone to come up with a a dual mass or roller locked delayed blowback 9mm upper.

[wgj3]

You can bet there are people out there already trying to build a better mousetrap.

 

I shoot with a chap who does some amount of his own gun work and we were recently discussing his foray into this topic. He's planning to use a 5.45 bolt in his trial and see where it goes from there...

 

or you could snag one of the new semi-auto MP5 clones for a smooth $2K and go from there...