Originally Posted by kiwi3006
I was speaking to a guy once who shortened a barrel so he could fit a suppressor on it. Once it had been shortened the accuracy decreased. He put it down to the projectile doing less than one and a half revolutions while in the barrel. ie a 1 in 12 twist needs to be 18 inches long to get 1.5 revolutions in the barrel.
Anyone else heard of this? Or was it more likely a poor crowning job when the barrel was shortened?
I would be more inclined to believe that it was the crown or more likely when he shortened it
the harmonics changed and he should have worked up new loads.
Also by shortening the barrel he lost some velocity and should have increased the powder
charge or changed powder in order to reach the "OLD" velocity.
Lots of rifles shoot there best at just below the max pressure and velocity so if a rifle shoots
well the best thing to do is chronograph the existing load and after changing/shorting the
barrel work up new loads that match.
I learned what little I know from a master gun smith that shot nothing but bench rest and he
actually re crowned until he found the best harmonics (Shot the best). I know of one rifle that
he re crowned 11 times before he was satisfied.
J E CUSTOM