30 Remington AR upper.

[cal7.62x39]

So I ordered a couple of remington lowers off of CDNN and they are marked 30 RAR. The lowers can be built into standard 223/556 configuration, however they also come with stripped uppers in the same caliber. Shy of scouring the world for 30 RAR upper parts not in production anymore, is there anything I can turn the uppers into beyond paperweights? I think that the BCG and barrel extension size is going to make it non compatible with standard 223/556.

 

[cal7.62x39]

Well got my receivers today. I like them and would like to be able to use them as a set. The uppers are flaired out more in the BCG area, but are otherwise appear normal. If no one is sure if they can be shimmed, or made to work with a .223 barrel extension, is there a builder or gun smith someone could point me to to find out?

 

[SPDguns]

From WIKI: The rim size is.492" and because the round generates 55,000 psi, Remington opted to use a .308 rifle bolt in a 5.56 sized rifle for increased case support.[4] With a 150 grain bullet, the round travels at 2575 fps.[5]

 

[cal7.62x39]

It uses a standard AR-15 carrier group, just the bolt head is 30 cal. I think from what little is out there is can be chambered for 223. But the barrel extension is where things get difficult. I don't know if there's anyone out there that can make one, or a way to shim one. Or if I'm just SOL and need to just start with different uppers.

 

[SPDguns]

Have a sleeve machined???

 

[AKguy1985]

Isint 6.8 SPC based on the. 30 rem AR?

 

[Duckhunter39480]

The 6.8 is based in the "old" 30 Remingtom, not The newer "30 Remington AR". Two totally different cartridges.

 

[Kbh12381]

Do you still have the uppers?