By the way, an aside...pushed from the same case, with the same powder charge, a larger diameter bullet of the same weight will always yield more velocity. It's a bigger piston, therefore more energy gets transferred to the projectile (not to mention that the twist rate is generally less, a not insignificant distinction as better than 25% of the energy released via combustion is consumed in bringing the bullet up to rotational speed...this is why ultra-velocity projects, wherein one is trying to attain the greatest projectile velocity possible, always involve non-rifled bores...some of these get surprisingly close to the gas velocity, which is on the order of 7,000 fps...which is why muzzle brakes can be so effective (F=ma -> consumed powder in the form of a gas escaping the muzzle at around 7,000 fps)).