http://www.gunproof.com/Proofing/proofing.html
"Proof regulations require that shotgun barrels shall be struck-up and smooth and that insides shall be clean. Pitting should be removed so far as is practicable, bulges knocked down and dents raised."

Could one of our British brethren please explain why? Is "practicable" wall thickness dependent?

Last edited by Drew Hause; 03/05/12 08:35 AM.