Piston AR Build Lower Reciever Questions...

[Hungarian_Legionnaire]

I'm starting a step-by-step, part-by-part, M4 Piston Build, & I had a few questions about the Lower Receiver.

Since I'm building a Piston M4, Do I need a Specific Piston Lower Receiver ? Since the Lower Receiver doesn't need the Buffer-Tube Is there a M4/M16 Lower Receiver, that doesn't require a Buffer-Tube & have something more like a folding stock. What goes in place of the empty Buffer-Tube, is it just hollow, or is there a block ?

I plan on starting out on the purchasing a Bare Lower Receiver & building it as I have money, part-by-part. Also do I have to purchase the same Manufacture Piston driven Upper Receiver as the Lower Receiver ?

I would also like any recommendations of Piston Uppers and Lowers

Thanks for any help.

[IronColt]

regular LR will do. your 6 position stock will be attached to the buffer tube.

[7.62 Charlie]

http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=442

http://www.para-usa.com/new/product_rifle.php

I think both the RRA PDS and PARA TTR are only sold as complete rifles.

[arsilva32]

you will need a buffer tube (reciever extension) regardless if its a piston build or DI set-up.the BC still travels rearward into the tube.the piston set-up is assembled on the upper reciever,so most lowers are ok for a piston build. my piston pistol is sitting on a regular spikes run of the mill lower,works flawless.

[rareair]

I plan on starting out on the purchasing a Bare Lower Receiver & building it as I have money, part-by-part. Also do I have to purchase the same Manufacture Piston driven Upper Receiver as the Lower Receiver ?

No, most AR parts are interchangeable with one another. But if you like to match, check out Stag, POF, Spike Tactical & Adams Arms'. They all sell piston's uppers and lowers separately

[762.DEFENSE]

Any LR will do, unless you have matching ocd like I do. Then follow the above advice on going with a company who producecs both the upper and lower.

[emy]

If your building a piston AR from diff. supplier be ready to do a lot of work to match all those diff. parts. I had to do a lot of back and fort to the range to get it to work properly , had to open up the gas port in the barrel to cycle the piston. The original port wasn't big enough. I used the AA kit for my build on 7.62x39, maybe 223 less problem, 223 has higher pressure than 39.

[Outta Control]

If your building a piston AR from diff. supplier be ready to do a lot of work to match all those diff. parts. I had to do a lot of back and fort to the range to get it to work properly , had to open up the gas port in the barrel to cycle the piston. The original port wasn't big enough. I used the AA kit for my build on 7.62x39, maybe 223 less problem, 223 has higher pressure than 39.

I think doing some research before actual build would help. For instance AA kits specifically calls for a .750 diameter gas port, which is fairly standard for most 16" barrel but I have found that the DD lightweight barrel they offer only has a .625 gas port. Which means you have to either drill out to .750 or you'll have cycling issues. Also I believe AA stated that their current piston kit is not designed for a 7.62.

Per their website:
"Q. What calibers will the Adam’s Arms systems work with?

A. Currently our system will function with the 5.45x39, the 5.56/.223, the 6.5 Grendel, and the 6.8 SPC without any special modifications needed. We are in the testing stages right now with the .308/7.62 NATO and will update our website when we have a system that will work to our standards."

[wash]

As others have said, you will need a buffer tube.

Kill two birds with one stone and buy a PWS enhanced buffer tube to prevent carrier tilt.

[Outta Control]

I think the issue about carrier tilt has gone the ways of the Ford Pinto. I've ran close to over 2K rounds on my MEGA/AA rifle and have no signs of any carrier tilt.

[Hungarian_Legionnaire]

I saw many videos on YouTube that even the RUGER, LWRC, STAG ARMS & other high dollar Piston-Driven M4 uppers suffer from Carrier-Tilt, which needed a "Buffer Assembly" that holds the rear of the bolt carrier centered in the receiver extension during the linear motions of recoil and battery thus potentially preserving the life of barrel extensions, bolts and bolt lugs, extractors, receiver extensions and the bearing surfaces inside the upper receiver... Has anyone came across this before ?

[Droppin Deuces]

Carrier tilt is kind of a thing of the past. Different companies have come up with different version of the same remedy, which is to build stabilizing ramps on the underside of the bolt carrier.
I've put many thousands of rounds through an Adams Arms upper with no signs of carrier tilt.

[missiontrails]

Para Ordnance and Sig are the two that don't use a buffer that travels back into a tube... Well, and the SCAR also.. Any home build scenario will be just like a DI.

[Don29palms]

I think doing some research before actual build would help. For instance AA kits specifically calls for a .750 diameter gas port, which is fairly standard for most 16" barrel but I have found that the DD lightweight barrel they offer only has a .625 gas port. Which means you have to either drill out to .750 or you'll have cycling issues. Also I believe AA stated that their current piston kit is not designed for a 7.62.

Per their website:

I would strongly suggest against drilling your gasport out to .625 or .750. .625 and .750 respectively are the barrel outside diameter dimensions where the gas block sits over the gas port in the barrel. You don't have to modify the gas port in the barrel at all if you are using the kit for what it is designed for.

[Outta Control]

I wouldn't either but apparently some folks have done this.