Minimise torque damage by isolating as much of the barrel as you can.
Beg, borrow or steal (or buy) a barrel vice or barrel clamps. Whatever you decide, DONT use those plastic upper clamshells to crank-up a muzzle device. Some more talk on this subject in the archives.
![[Image: barrel%20vice_zpsjibwvkgr.jpg]](http://i1374.photobucket.com/albums/ag436/stupidbernard/barrel%20vice_zpsjibwvkgr.jpg)
Are you using a crush washer to time that brake?
BTW...Your brake coming loose might have little to do with the shape of that group.
Beg, borrow or steal (or buy) a barrel vice or barrel clamps. Whatever you decide, DONT use those plastic upper clamshells to crank-up a muzzle device. Some more talk on this subject in the archives.
Are you using a crush washer to time that brake?
BTW...Your brake coming loose might have little to do with the shape of that group.