So my neighbor, bought at an auction, all of the reloading equipment for rifles. He was reloading .243. On a factory box of .243 shells it showed the muzzle velocity over 3000 fps. However, looking at the same weight bullet (80 grain), none of the muzzle velocities were even close, no matter what the powder, from the book. Why is that? I remember back in the days of reloading shotgun shells I could reload shells, according to the specs in the book, that were much faster than the factory shells.
Other question is, why with some powder you can go up to say 42 grains and have a fast muzzle velocity but with other powders you can only go to 39 grains and have a slower velocity?
Other question is, why with some powder you can go up to say 42 grains and have a fast muzzle velocity but with other powders you can only go to 39 grains and have a slower velocity?