.308 Build

[INhondo]

I've read many threads on multiple sites so I felt I was prepared for this build. In fact, I still feel I'm prepared. Parts include: DPMS assembled upper, DPMS lower and DPMS lower parts kit. Ballistic Advantage 16.5" barrel and EGW free float forearm. My goal is to have an accurate, mid-level, minimal frills build. I trued the receiver face and shimmed/thermo fit the barrel. I know, not mandatory, but I wanted to so I did it.
Minor problem! Do you have any idea how many different barrel nut/wrench patterns there are? I'm disregarding barrel nuts that use a claw wrench for torqueing. There are 24 hole, 22 hole and 20 hole barrel nuts. The EGW barrel nut fits nicely to the upper, no slop so I contacted them and the wrench they used is "discontinued". I've ordered a PRI DPMS pattern 4-pin barrel nut wrench with a bolt circle radius of 0.86"/bolt circle diameter of 1.720". It was nearly $10.00 cheaper ordering directly from them than from Brownell's. The EGW 20 hole pattern barrel nut has a bolt circle radius of 0.869"/bolt circle diameter of 1.738", probably close enough.

 

[INhondo]

308 Build

I finally found a barrel nut wrench to fit my two free float handguards I have on hand and the barrel nuts would not align. Rather, they were aligned at the 3 o’clock and 9 o’clock positions when torqued but not at the 12 o’clock position. In other words the radius for the gas port holes was too long.
I bought a 9 ”octagonal carbon fiber free float handguard where the gas tube passes over the barrel nut rather than through the barrel nut, success. The AR-15 gas tube is long enough and didn’t require any bending to fit.

 

[INhondo]

Just playing around today after installing a Miculek muzzle brake. I checked the gas key to gas tube fit, perfect. I was unable to feel any snagging when easing the bolt carrier forward when the gas key captured the gas tube.

 

[daddyusmaximus]

Sounds good so far. That issue with the barrel nut was weird. A lot of times when you buy a rail system, the company will have a barrel nut that's proprietary, and they'll ship you a wrench with the set. I used Midwest Industries, and they do that.