Originally Posted by Mach3
My other question:

Is 1/2"x28 an acceptable substitute for 13x.75? Would this make the barrel wall too thin for a .270 caliber?

There's only .020" difference in diameter between 13MM and 1/2". That's about 10 strands of hair stacked up together. The barrel won't know the difference.

Ignorance can be fixed. Stupid is forever!