Barrel Nut Torque

[Rock Head]

I'm building my first AR and when I torque my nut to 30 ft/lbs the gas tube does not line up. If I back it off the nut seems to loose. I have gone up to 45 ft/lbs with a ways to go before I clear the barrel nut and align the gas tube. How high can I go?

Thanks in advance for your advice

 

[noz455sd]

Re: Barrel Nut Torque

I believe 40 is max and 30 is your starting point...If you cant hit it between 30 and 40ftlbs you need to shim it

 

[M25BeastShooter]

Re: Barrel Nut Torque

The Army TM on the M16 recommends 36-65 ft lbs. I find that if you torque the barrel loosen it up and re-torque it it will "work" it in. Make sure you use an anti-seize grease like moly grease on the threads of the barrel nut

 

[noz455sd]

Re: Barrel Nut Torque

Ok dang see I didnt know that but I did see the 30 to 40 range somewhere and I believe it was said that the greatest accuracy could be attained between that range or some garbage like that...but yeah the moly grease is a must too...I got mine down at the auto parts house

 

[NoFail]

Re: Barrel Nut Torque

Work it in like guy above said. That said, mine is torqued to high heaven and it's just fine.

 

[LongArm]

Re: Barrel Nut Torque

Put it on and torque, then take it off and re-due. Try this about 3 times. This will help it seat the barrel and it wears the coating on the threads to help it tighten better. I have built them with 80ft of torque before with no ill effects. I would try for around 65ftlbs. I think 40lbs to 70lbs is the sweet spot. Over tightening can cause the barrel pin in the barrel extension to bend or mess up you receiver.

 

[1791PrecisionArmory]

Re: Barrel Nut Torque

Nothing leaves my bench under 40ft lbs, 40-50 is the sweet zone from my experience with 16-20 inch barrels.