CMT Upper for precision build

[jumrobe]

Im working on putting together a precision upper for an AR15. It’s going to consist of a a 20” Krieger barrel coming from CLE, a Burris XTRIII 3.3-18x50, and a 17” IWI ARCA handrail. BCG will be an Azimuth NiB overrun. What I haven’t decided on is the upper. I understand that there may be some accuracy to gain by going with a beefier upper to increase stiffness.

For the upper, I’ve been eyeing the CMT UPUR-2 for this build. Has anyone used CMT uppers for precison builds?

I’ve used ADM uppers in the last with good results, but I wouldn’t mind saving $100 if the CMT uppers are also good to go.

 

[JS8588]

CMT uppers are well machined, but not a thermal/press fit. I have two of them. I've read conflicting reports on the ADMs being so.
For a precision build, I'd probably pick up a Mega and be done with it.

 

[jumrobe]

CMT uppers are well machined, but not a thermal/press fit. I have two of them. I've read conflicting reports on the ADMs being so.
For a precision build, I'd probably pick up a Mega and be done with it.

That’s good to know. Is thermal fit hyper critical for accuracy? I’ve read all manner of conflicting reports.

The ADM’s I’ve used required press fit with Criterion barrels.

 

[JS8588]

Hyper critical? No. You spent Krieger $ on the barrel, though. It deserves a thermal fit upper.

 

[jumrobe]

Hyper critical? No. You spent Krieger $ on the barrel, though. It deserves a thermal fit upper.

That’s fair. Are all of the Zev/Mega billet uppers thermal fit?

 

[JS8588]

They are, as are SOLGW, & Grey Ghost Precision.

 

[Bluedog82]

^BCMs as well, and you can get blems for $60.

 

[jumrobe]

^BCMs as well, and you can get blems for $60.

Looks like they’ve got some in stock. Might buy a few to try out.

I also saw in the thermal fit upper thread a reference to Precision Firearms uppers being thermal fit. Their upper looks very nice, but I can’t find anything about them in reviews.

 

[JS8588]

I have one of those too. Heavier than you need. I bought one for a 7.62x39 AR build. It's a hog hunting gun so weight wasn't super important. The BCMs are thermal fit, but no beefier than any milspec standard forged

 

[jumrobe]

That’s good to know. This gun is going to be used to shoot gas gun competitions so I’m not super worried about weight, but realistically don’t want it to be 18lbs either.