New upper build with pics

[cr5]

So I figured that since I have this non restricted length 6.8 SPC barrel sitting around for my ACR and no time to fiddle with the bolt and extractor to make it function and also little desire to do it since my 300 Blackout non restricted conversion is treating me so well that I'd throw the 6.8 into an AR and see how it shoots.
I went into Tier One Armoury and bought a new Daniel Defense upper, a YHM low pro gas block, and a new stainless mid length gas tube. Found a Daniel 6.8 SPC bolt on the EE for a decent price. Pulled out my NEA FA bolt carrier (bolt went into the parts bin), a spare charge handle left over from a previous BCM handle upgrade and slapped it all together to make this.

Barrel specs, Questar built stainless 1:11 twist with SPC II chamber

All that's left is to select and buy a forend and I'll be out shooting
I'm leaning towards an AP Custom carbon fiber forend from Phoenix in Edmonton but haven't decided quite yet.


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This will also be my just in case the NFA pulls off a miracle and the AR goes NR upper for deer hunting

 

[F22_RaptoR]

Just make sure you measure the gas port size.

When Questar sold me one of their "take-off" ACR barrels (as a regular AR15 barrel) the gas port was only 0.040", half of the diameter it should be. If the 6.8 barrel is based like anything off the ACR factory barrels, you may be way under gassed.

ETA

Just took a peek on some forums, and most guys running 20" guns with rifle length gas systems are using ports between 0.105" and 0.098", so that should give you an idea if it's around the right size. The ACR barrel will use a mid-length gas system, so it'll be a teeny bit smaller than that.

 

[Trinimon]

Look'n good!

 

[cr5]

Just make sure you measure the gas port size.

When Questar sold me one of their "take-off" ACR barrels (as a regular AR15 barrel) the gas port was only 0.040", half of the diameter it should be. If the 6.8 barrel is based like anything off the ACR factory barrels, you may be way under gassed.

ETA

Just took a peek on some forums, and most guys running 20" guns with rifle length gas systems are using ports between 0.105" and 0.098", so that should give you an idea if it's around the right size. The ACR barrel will use a mid-length gas system, so it'll be a teeny bit smaller than that.

I'll know and adjust it as required once I get it to the range. My Questar 223 ACR barrel functions perfectly and when I built my ACR 300BLK conversion barrel I had Suputin drill the gas port to 0.1, I ended up opening it up to 0.125 to get it to cycle everything, I built the 300BLK with a carbine length gas system as well.

Eventually this barrel will be pulled and I'll complete the ACR conversion but I put it in here to see how it shoots and start some load development with it. I also have a 16 inch factory ACR barrel that will probably replace this one once I have some time to tune the extractor in my ACR 6.8 bolt.