Is there any info on a piston 6.5 Grendel out there?

[TacBlade]

I have one of the new Adams Arms piston setups and was thinkin about trying it on a 6.5 Grendel build?

[mongoosesnipe]

Should be fine lighter loads may not have the gusto to cycle but you are not going to hurt anything although DI guns tend to be more accurat and I can't imagine the scenario of firing so many Grendel rounds without cleaning such as to warrant a piston set up

I seem to recall alexander arms having a piston driven upper on there web site at one point you may want to call and ask them about it

[montana]

I had an 18" AA Grendel barrel that came with an over sized gas port making it over gassed so I installed a Adam Arms piston and being self regulating it ran flawlessly. Alexander arms sold piston rifles using Adam Arms pistons at one time but I don't know if they still do. I have since then removed my Adam Arms pistons from all of my rifles but one and switched to adjustable gas blocks like the SLR Senrty 7 "my favorite" or the Syrac which is made by the maker of the Adam Arms gas pistons. Gas piston AR's are heavier, recoil harder and tend to be less accurate compared to the DI system. But to answer your question Adam Arms gas pistons will work on 6.5 Grendels. If you already have a Adam Arms gas piston and wish to use it your not out anything by trying it. I personally would recommend a DI system with an adjustable gas block if starting new. Monogoosesnipe may have a point about lighter loads as I do remember other members having problems with short stroking do to small gas ports while using AA gas pistons but I personally never experienced this problem . Hope this helps.

[Klem]

+1 Montana.

I have used the Adams Arms and have found absolutely no benefit to the extra cost and weight forward of the balance point. The sizeable gas block also limits your choice of handguards to pretty much the length of the gas system. They run flawlessly, but so does a well tuned DI system. Suppressed, they are of no benefit as most of the gunk comes back from the chamber into the receiver. It is not my experience they are less accurate than DI, but certainly no more accurate. To be fair there is ongoing debate about this.

The AArms uses a collet that you hammer into the upper. This is as good as permanent so I am stuck with an upper I can only use with Mr. Adams. With the benefit of hindsight I should have stuck with DI.

It does seem that gas pistons are a sort of a fashion that has had their time and are now in slow decline. Adjustable gas blocks are replacing pistons as the latest AR innovation.

[TacBlade]

Thanks for the info guys! I do have one of the new AA piston setups for a pistol. Pistols are "loud" and ammo burners! I can change out the rod to work with any length of system. I have the upper with that collet pounder into it also and I'm not sure if it will come out, but it should with a punch. Since I have it, I may try it out?

[tango29]

I put together a piston setup
AA 24 in barrel
Mega Billet upper/lower
Adams Arms Rifle length piston kit
Samson Star-R hand guard
Geissele HS NM DMR trigger
PSR stock

Had problems with FTE
Filed down extractor an replaced buffer
Works like a champ.accuracy is great

[LRRPF52]

I saw that LWRC, a staple company in the op-rod driven AR market, had introduced some DI models this year at SHOT. They're using the same bolt carrier and key tower design as the DPMS GII:



I also notice that several of the companies or persons who have been deeply involved in the latest wave of op-rod driven AR's use DI guns in their training courses, usually a Mid-length Gas System in a well built carbine.

There have been 3 periods in AR15 history where op-rods were pursued (1968 with the Colt 703, the 1980's with the RHINO conversion, only to be abandoned and never catch on with the market, until this last one with the HK XM4, which evolved into the HK416, and the band wagon that followed. I actually helped source some of the peripheral parts for the HK XM4, but there were certain requirements for that program that are not what people think, and a lot of it had to do with submersion, suppressed use, and full auto.

Here's a good article on the matter: http://vuurwapenblog.com/2009/10/21/the-...onversion/

[TacBlade]

To offset the weight forward, I am getting a Proof Research Carbon Fiber wrapped barrel.

[jkingrph]

I have two, a mid length and full length rifle using the Adams arms system. Both run great, digesting everything I have put through them, even reduced fireforming loads which feed from the magazine and cycle the action.

[cjgemm]

I just added one to a 12.5 SBR. 100 rnds of suppressed fire, gas system set on 25% Almost no cleaning afterward...

I see myself shooting this upper a Lot more.

[MKo]

what's the suppressor you got on picture?

[cjgemm]

SWR Omega 30.