.223 piston & polymer

[phil evans]

added adams arms, piston, 1 in 7, melonite, upper to new frontier polymer lower.
its a experiment, did due diligence as to why frontier arms and adams arms.
want to see what it's all about with pistons?
will see if things start crumbling/cracking/melting.

yesterday, 60 down range- no problems at all.
trigger very heavy, maybe ~10 pounds.
~ 2.5moa with factory.

new frontier armory will send me a lighter trigger spring.
already mollied trigger surfaces to see how that works.

[Darreld Walton]

I used a New Frontier lower last year to build a dedicated .22 LR with a CMMG upper. I had to replace the hammer/trigger setup to a non-notched outfit to work with the CMMG bolt. I also stepped up and put a RR two-stage into it at that time. I also, from time to time, swapped the upper for an M4-type that I'd put together, and didn't have a single problem with it. It didn't loosen up, burn down, melt, distort, have the holes loosen up, and for under a C note when I bought the thing. I have no problem whatsoever buying another one.
I too have it in mind to go with a piston setup at some point, but just got hammered with a big tax bill from the state, so it has to go on the back burner for awhile.
In the meantime, the New Frontier lower now wears a collapsible butt, and with the .22 LR upper, has become a favorite of the Grandkids!!!

[p246]

If you shoot a lot of hot stuff watch for wear under the top of upper receiver due to bolt tilt. Not manufacturer specific just a design issue in AR's that have op rod/pistons designs added.

[S.B.]

Are these legal in Service Rifle competition? Just me but, I don't see the need? I always thought Eugene Stoner a pretty savvy hombre, his stuff has lasted in our military history far longer than most.
Steve

[Jim in Salt Lake]

Piston uppers aren't legal in service rifle, either NRA or CMP. In NRA they'd be classified as a match rifle. For across the course competition, I don't think the piston system give you anything other than more complexity and more stuff changing barrel harmonics.

[Tuna]

And as one well known maker of AR-15 rifles said that it's something else that can go wrong on a system that was never designed for it.