Originally Posted by coach71
What are the chances of a guy being lucky and just spin it on and it be headspaced correctly?
Zero.
Quote
Or will the thread length and shoulder need work?
Yep.. Breech-to-shoulder distance is short on the M77.. Would need to be lengthened about .030-.035, depending..

Ex- USN (SS) '66-'69
Pro-Constitution.
LET'S GO BRANDON!!!