6 or 6.5cm rebarrel?

[Jnull]

Earlier this year I bought a complete aero AR-10 lower and a stripped upper with an 18” 6.5cm mid length gas barrel. It was cheap and available so I bought it knowing I’d put a different barrel on it.

I’m running a JP low mass/high pressure bolt, JP H2 SCS and a superlative arms adjustable gas block. I’m looking at a carbon proof 22” +3 gas in 6 creed, any issues with a +3 in 6cm with the parts I currently have? I also have a dedicated Hyperion K for it that got approved yesterday. Thanks guys.

 

[bfoosh006]

Proof recommends..

Recommended components:


Full Mass Bolt Carrier Group
Full Mass Buffer
Adjustable Gas Block

However, I would like to think a +3 barrel, would lower the gas port pressure quite a bit.

What are you going to use the 6MM CM for ?, that the 6.5CM can't do ?
I would check on ammo availability for both, and remember a 6MM CM is going to burn the barrel out sooner .. ( just sayin' )

 

[bigjake83]

Proof recommends..

Recommended components:


Full Mass Bolt Carrier Group
Full Mass Buffer
Adjustable Gas Block

However, I would like to think a +3 barrel, would lower the gas port pressure quite a bit.

What are you going to use the 6MM CM for ?, that the 6.5CM can't do ?
I would check on ammo availability for both, and remember a 6MM CM is going to burn the barrel out sooner .. ( just sayin' )

Damn you!!

I made mine Grunt proof...lol

Same question as @bfoosh006, why 6MM? Also keep in mind the 6MM have been more prone to feeding issues so I would absolutely blend those feed ramps.

 

[stprelle]

I run a +2 gas system with a 6 creedmoor proof bbl superlative block and aero upper and lower. No feed issues or anything negative to say. Good combo in my opinion.

 

[Jnull]

I know what proof recommends but I also know plenty of guys running the low mass carrier and scs to help fine tune things.

As far as 6 goes it’s mostly personnel preference but I read some guys on here having problems with the 20” 6.5cm proof barrels so I was going to stay away from those.

 

[Jnull]

I run a +2 gas system with a 6 creedmoor proof bbl superlative block and aero upper and lower. No feed issues or anything negative to say. Good combo in my opinion.

What barrel and length?

 

[Jnull]

I bitched out and went with a 22” 6.5 cf proof. Really wanted to go 6cm but read about a few feeding issues after doing some more research and that pushed me away.

For anyone looking check out front range precision, by far the best price I could find currently on a proof barrel with their sale.

 

[lennyo3034]

Every single 6mm large frame barrel I’ve had (JP, proof, craddock) has had feeding issues. Craddock has redesigned the barrel extension which greatly helps but the bullet tips still occasionally get dinged when chambering. The JP would actually not chamber some bullets at all. Proof was somewhere in between, not sure if they have standard extension or 6mm specific. The 6CMs seem to be far less forgiving to being outside of “optimally gassed” than the 6.5s.

 

[lennyo3034]

Once I shoot out my Craddock 6CM and proof 6CM barrels I’m going back to 6.5, probably Craddock.

 

[Jnull]

Yea I went 6.5, glad I did. Thanks for the help guys.