Short Barrel Gas Piston AR

[eleaf]

Looking to perhaps replace my standard 16" AR, but I want to replace it with a short barrel gas piston upper chambered in 6.5 grendel.

What is going to be the best way about building something like this?

I have never done a build from scratch so I have no basis of information.

Thanks.

 

[nw911guy]

Re: Short Barrel Gas Piston AR

How short a barrel?

 

[eleaf]

Re: Short Barrel Gas Piston AR

12" or less. Preferably around 10". Maybe even as short as 8".

Alexander Arms sells a 10" gun, but it's DI. The gas piston guns they sell all have long barrels.

Looking for something like the LWRC PSD, but in 6.5 Grendel.

 

[shoepop]

Re: Short Barrel Gas Piston AR

Get a barrel and bolt kit from someone like Alexander, then get an Adams Arms piston kit in correct length from someone like Brownell's.

 

[ZLBubba]

Re: Short Barrel Gas Piston AR

This is an intriguing project, eleaf. Why are you going with a Grendel over the 6.8mm or the 5.56? Good luck, and keep us posted (with pics!).

 

[m1garand30064]

Re: Short Barrel Gas Piston AR

Or just get a POF and be done with it. I know POF makes some very short uppers. I have a P12x recon and I am very satisfied.

Edit: Nevermind. POF does not make an upper in 6.5. Sorry for reading too fast!

 

[sobrbiker883]

Re: Short Barrel Gas Piston AR

Why take away the 6.5G's advantage by robbing its speed?

 

[ORD]

Re: Short Barrel Gas Piston AR

Building a complete AR upper is not terribly difficult to do with the proper tools for the job and some patience (since its your first build).

The easiest thing to do is buy the components, minus the gas system, and assemble them yourself along with an Adams Arms piston retrofit kit in the proper gas system length for your purposes. I would recommend you get a 10.5", 1:7.5 twist barrel to adequately stabilize the Grendel with a short barrel and to afford you the best accuracy potential. With a 10.5", you get the benefit of a carbine length gas system with which you can use Adams Arms' Carbine Piston Conversion kit.

As for a barrel source, check with Satern Machining, Sabre Defence and AA to see what they can do for you.

The other option is to buy this:

http://www.alexanderarms.com/item/10/91/65Grendel105Tacticalcompleteupperreceiver.htm

and this:

http://www.adamsarms.net/details.asp?sku=CPS-D-ADA

and follow Jason's instructions on converting your upper with the Adams Arms' kit.

 

[nw911guy]

Re: Short Barrel Gas Piston AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">Why take away the 6.5G's advantage by robbing its speed? </div></div>

X2 kind of curious. Seems like a 6.8 would be a better candidate.

 

[eleaf]

Re: Short Barrel Gas Piston AR

To not have to reload for yet another caliber. I have a 6.5G in a 20" barrel for a long range monster.

Everything I have read about the 6.5G is that it performs admirably well with a short barrel, and has more than enough energy at close distances.

 

[eleaf]

Re: Short Barrel Gas Piston AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body">Building a complete AR upper is not terribly difficult to do with the proper tools for the job and some patience (since its your first build).

The easiest thing to do is buy the components, minus the gas system, and assemble them yourself along with an Adams Arms piston retrofit kit in the proper gas system length for your purposes. I would recommend you get a 10.5", 1:7.5 twist barrel to adequately stabilize the Grendel with a short barrel and to afford you the best accuracy potential. With a 10.5", you get the benefit of a carbine length gas system with which you can use Adams Arms' Carbine Piston Conversion kit.

As for a barrel source, check with Satern Machining, Sabre Defence and AA to see what they can do for you.

The other option is to buy this:

http://www.alexanderarms.com/item/10/91/65Grendel105Tacticalcompleteupperreceiver.htm

and this:

http://www.adamsarms.net/details.asp?sku=CPS-D-ADA

and follow Jason's instructions on converting your upper with the Adams Arms' kit. </div></div>

I've considered that, but I want to make sure that I can use rail handguards, and not he one that come with the piston conversion kit. I don't know that I can do that with this setup.

 

[sobrbiker883]

Re: Short Barrel Gas Piston AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: eleaf</div><div class="ubbcode-body">To not have to reload for yet another caliber. I have a 6.5G in a 20" barrel for a long range monster.

Everything I have read about the 6.5G is that it performs admirably well with a short barrel, and has more than enough energy at close distances. </div></div>

Cool, I know you're not one of the "dirt shooters"...having another is always a good reason!

POF should make their gasblocks mountable with set screws or offer a two-pice clamper style, it'd be sweet for applications like this.

 

[KYS]

Re: Short Barrel Gas Piston AR

Funny that you post this. I am still waiting for my paperwork to show up on my lower but I am gathering parts for a 12" 6.5G SBR. I have been told from the 6.5 guy at Satern that you will struggle to have a reliable setup in anything shorter then 12".

When I get it back and running I will post up some info and a video.

 

[eleaf]

Re: Short Barrel Gas Piston AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KYS338</div><div class="ubbcode-body">Funny that you post this. I am still waiting for my paperwork to show up on my lower but I am gathering parts for a 12" 6.5G SBR. I have been told from the 6.5 guy at Satern that you will struggle to have a reliable setup in anything shorter then 12".

When I get it back and running I will post up some info and a video. </div></div>

Excellent.

 

[ORD]

Re: Short Barrel Gas Piston AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: eleaf</div><div class="ubbcode-body">I've considered that, but I want to make sure that I can use rail handguards, and not he one that come with the piston conversion kit. I don't know that I can do that with this setup. </div></div>

A carbine-length AR-15 handguard is a carbine-length AR-15 handguard. You need to make sure of the length as some HG manufacturers make extra length, short length, etc. HGs. The big problem is whether the AA piston conversion will work with the HG you want to use. Just consult with AA for the HGs that they know will work with their kits. They have a list of "problem" HGs and a list of those that are known to work without modification.