AR10 problem

[19Charlie_84]

Ran into a hickup in my AR10 build. Using a Fulton Armory upper receiver and Daniel Defense Lite Rail. The DD barrel nut would not thread onto the receiver threads but only 2 turns and stop. I took it to One Hole Gunworks and he measured the threads to find the receiver is 16tpi and the nut is 18tpi.

I dont have a tap and die set, although my dad does in IL. Another gross f*ck up of the .308 AR manufacturers in not standarizing across the industry. Also I cannot find barrel nuts of any kind online.

Rock River uses a special thread on thier LAR-8's saying use only specifically designed ones for that rifle due to thread depthness. (again, non standard, too easy to fix. get together and say x measurement is standard) They sell YHM, Surefire, and DD rail handguards on thier site in the .308 section so one would think they would sell ones that will not result in shooter severe injury or death.

I have emailed DD asking if they make different threads. Fulton does not have an email address on thier site. Any other thoughts before I go insane? This proprietary bull $hit is getting out of hand.

[drine]

No help here other than feeling your pain. Too many makers, making things different.

[19Charlie_84]

After talking with a dude at the Waco gunshow, and Mike at Tactical Inovations, then consulting the DD website to confirm...there is in fact 3 versions of barrel nut out there. Armalite, DPMS, and RRA all have different tpi's, pitch, and depth. Wait till Monday and order a new nut I will do.

Word to the wise, ensure compatibility before purchasing firearms parts.

[hunter_la5]

Sorry to hear that bro. Unlike AR-15's, there is not very much in the way of standardization of specs/dimensions across manufacturers for AR-10's/.308 AR's. Most manufacturers, as far as I can tell, build their own rifles to their own specs, so parts are often not interchangeable between .308 AR's of different makes.