Quote Originally Posted by Robinhood View Post
The barrel is usually about .010" off the rim of the bolt head. So if you close the bolt(with the bolt head you are going to use), screw the barrel with the nut and the recoil lug into the receiver until it makes contact with the bolt head you are within .010" plus or minus where the barrel will end up at correct headspace. Once you run the nut down to contact with the recoil lug, you will have a good indication of how many threads will be exposed if any.
Thanks. Misspoke, I was thinking boltface and not rim...