Arms Tech Gas Trap?

[Armati]

Does anyone know anything more about these?:

http://www.armstechltd.com/products.php?id=compak16

From what I gather, it uses an expansion chamber (baffled?) to feed the gas system instead of drawing hot gas directly from the bbl. This is just brilliant! Why is no one copying this design? Are their any pics that show the internal details of this system?

[ADC]

I know the first M1 Garands were of a gas trap design, but were replaced with a gas port after a few years.
I am curious as well, any one shot one of these gas trap ARs, web site say they have been making them since 1991?

[JoshNC]

I know the first M1 Garands were of a gas trap design, but were replaced with a gas port after a few years.
I am curious as well, any one shot one of these gas trap ARs, web site say they have been making them since 1991?

I've shot one of their shorty models on auto. Subjectively, it feels exactly the same as the standard AR/M16 gas system and I can perceive no differences. I only put one mag through the system, so I don't really have any real trigger time to speak to its reliability, etc..

The owner of the range where I used to work part-time really likes the Armstech system and has a few of their uppers. One (a shorty 9 or 10 inch) that he keeps on a post-sample M16A2 lower, the other (a 16 inch) which he uses for three gun matches.

As for Armstech's claims regarding the additional velocity and benefits of their polygonal gain-twist rifling, I think its benefits over standard rifling are marginal. I don't have any data on extended firing cycles, the life of the barrel, etc.. compared to traditional rifling. In theory the gain twist should reduce barrel wear, but I cannot speak to this.

It is an interesting system, though I don't know what it actually gains over the traditional DI operation and rifling.

[jmart]

Threefeathers has posted a couple of times about his.

Benefits are better gas control and the system runs a bit cleaner. Cyclic rate with their Compak-16 SBRs (either 9 or 10" barrel) run around 650 rpm IIRC. There's no port wear either so performance stays consistent over the life of the barrel.

As long as you run decent ammo through them, they run from what I gather.

[Armati]

The two biggest advantages would seem to be that it would not suffer from gas port erosion and it does not over gas the DI system in SBRs. Crane reliability packs, M4 feed ramps, and mid-length gas systems all exist because SBRs over gas the Stoner design.

[threefeathers]

Denny Hansen did a great review of this system in the April issue of SWAT. I gave him a reloading formula that allows him to get sub 1/2 inch MOA at 100 meters.

When Joe first came out with the system I was worried that it wouldn't stabalize the M 262 bullet. Boy was I wrong. My USR with a 14.5 inch barrel will take an eyeball shot at 100 meters with issue M-262 and the Black Hills 5.56 77 grain.

I've posted many pics on this site and don't have a lot of time now. (Actually I got accepted in Ayoob's LFI and am busy shooting the hell out of my LEM HK P2K)