Re: Why is max different in different rifles?
Land / groove diameters.
Land / groove area ratio.
Freebore dimension.
Lead angle dimension.
Brass fit to chamber dimension - how much energy is taken to expand case to chamber walls before remaining energy is used to propel bullet down bore.
Lets say the chamber is 0.472" diameter @ 0.200" above case head and brass measures 0.462" diameter, going to have 0.005"/side expansion before energy is used to propel bullet.
Factory chambers tend to be a bit more generous in body diameter then chambers cut for a custom built rifle.
Heck, even same barrel mfg'er with chamber cut by the same reamer and smith will exhibit different behavior. Typically not a huge variance but a variance in pressure/velocity for same ammo.
