barrel nut torque value

[foxx]

I torque mine to 2 or 3 good hammer blows. Never had one come loose yet.

Same here. Smack it and call it "good".

I doubt the factory nuts are measured for torque. I mean, the certainly could be, but they now come with crud in the threads (some say it is bluing salts, IDK) and they are crazy-stuck, but that isn't necessary.