Manufactured under the strict supervision of Mega Arms.
Chambered in .308 Winchester
Machined with a Medium Contour.
1×10 twist for accurate overall performance.
5/8-24 threaded muzzle.
.750 diameter gas block seat.
SR-25/DPMS pattern barrel extension.
11° target crown.
Uses standard AR-15 Mid Length Gas system.
GUARANTEED TO SHOOT SUB 1 MOA @ 100 YARDS WITH MATCH AMMO!!
Made from 416 Stainless Steel
Finished in Black Nitride Coating
Weight 41 oz
Does anyone have any experience with these barrels? I have seen concerns expressed in the past about nitrided stainless barrels, something about the heat treatment process having to be done a specific way in order to prevent the barrel extensions from possibly coming loose, but I am not very knowledgeable about such.
Any thoughts or opinions from experienced members would be greatly appreciated. Thanks.
I have one of the 18" ones. It is a nice barrel - general finish (including bore/chamber) is good, and it comes in a nice profile. It is reasonably accurate. I have not shot any factory match ammo through it, but some of my handloads with no specific load development were around 1 MOA right out of the box. So, I guess it lives up to its claim of “sub-MOA.” However it does not seem as consistently accurate as the Criterion 20" barrel (M110 profile) that I also have some time behind though.
Now, one problem I had was that the 18" is WAY, WAY overgassed. My specific combination is an SI Defense billet upper/lower, CMMG MK3 BCG, MI Gen II SS 12" rail, CMMG LPK, 308 A2 stock/buffer tube/spring, and 20-rd 308 PMAG’s. Initially I had a BCM non-adjustable GB, and a carbine RE with the DPMS 308 shorty carbine buffer and spring. This combo had frequent FTE’s, stovepipes, and FTF’s, and a funky 1 o’clock ejection pattern. It also ripped the rims off several cases, necessitating a cleaning rod to pound them out, and left serious extractor marks on all the rest. This suggested an overgassed condition to me.
After the swapping to an Kies adjustable GB, the A2 stock, and removing the 2 O-rings (I know, REMOVING the extractor O-rings actually helped!!!) under the extractor, it runs with 100% reliability. It has a good ejection pattern, 8’ at 4 o’clock, and brass comes out looking like new. Recoil was also reduced.
Hope this helps.
I can’t comment on the loose barrel extension issue related to the barrel coating - I don’t think I have experienced any symptoms.
Oh, for those preparing to build 308 AR’s - be prepared to do a little tinkering. There is NO “mil-spec” for these and IMO tolerances are much more variable for these than the standard AR-15. The previously posted review is a good example of that, parts swapping is even sometimes necessary!
Oh, and for those wishing to handload or shoot hotter ammo through a 308 AR - I would consider getting a barrel/bolt that is an Armalite AR-10 pattern instead of DPMS/SR-25. The DPMS bolts have a larger firing pin hole and primers from even moderate loads tend to crater. Just an FYI.