Since my name was used, I’ll jump in.
A few years back, CMMG did a run of middy barrels for me. These were the first middies available in 4150 with a 1/7 twist. I went with CMMG as lots of folks were running their barrels and everyone was very happy with them. One example that stands out was a report that Yojimbo wrote up.
Gas Port was located 1/8" too far forward as a measurement was made by them, or their machinist, from the wrong side of the flange of the barrel extension. While this, in and of itself, has not (to my knowledge) caused any issues, there were other issues that mainly revolved around poor accuracy on some samples and tight chambers.
My personal sample, as well as one that K9DPD has run, have been quite accurate. I know K9 was hitting golfballs with his at 100 yds with an ACOG IIRC. Mine, at 50 yds has always been more than accurate enough. However, with certain ammo, my personal barrel has started to experience some FTEs which evidence themselves with stuck cases. Mostly with Wolf, but I THINK I’ve had some with good brass ammo as well. Probably Remington from WalMart, but I’m not sure.
Near as I can figure out, as the tight chambers and poor accuracy were never root caused, is that either the chamber dimensions did NOT take into account the thickness of the chrome lining, OR the chrome lining is inconsistent thicknesses OR the reamer used to chamber the barrels dulled considerably during production of this run. Perhaps it is a combination of all 3 on some. I know that Steve from Adco and Mongo both experienced VERY poor accuracy, and I think keyholing from their handloads that have shot well out of every other barrel they’ve tried.
As it stands, I’ve got 4 barrels still sitting here. One is my personal barrel I’m still using, but will probably discontinue if I keep exeriencing stoppages (although I’m tempted to have Ned ream it with his 5.56 reamer to see what happens). The others are just expensive paperweights.
I have NOT tried any CMMG barrels since that time. Perhaps they have improved. However, from reports I’ve read here and on Lightfighter, it seems that tight chambers have plagued them on and off since my barrel were produced.
Some folks have good luck. For instance, I understand that KevinB has 1 or 2 SOCOM style barrels from them and they seem to run fine. Others are not always so lucky.
I did notice that in 2 of the gun rags this month, they had write ups on their products.
Jeff and John are good guys. They’ve got a nice setup there and run some good shoots. If they could improve their consistency, they could definitely compete even moreso than they do now.
I refuse to talk bad about them as they were good to work. My barrel experience was definitely not a good one, and I personally lost thousands of dollars on that thing. However, I do believe that it paved the way for others by demonstrating the viable market for 1/7, 4150 middy barrels. If nothing else, it has allowed others to enter that market and do quite well.
Giff
