Gunplummer
New member
P O Ackley did a test on bullet size and pressure. I do not remember all the details, but roughly: He re-cut a .30 caliber barrel with an 8x57 reamer. Apparently, there was really no pressure deviation as long as the neck and lead were 8mm. The pressure swaged the bullet to .30 caliber size. As for oversized bores, I still don't have a set opinion on that. I have owned quite a few rifles that I shot .308 bullets with great success that had .312 barrels. I would have to say bullet weight and velocity have more to do with some people's gun accuracy problems than a bad barrel.