To speak of such things where rifle powders are concerned, gets a bit tough because there�s so many rifle cartridges out there, which brings about a lot of variables. With handguns, it�s a bit easier because the sampling of both cartridges and powders is smaller. So let�s take a magnum revolver cartridge, say the more popular ones, such as .357, .41 & .44 magnums. With these powders, generally speaking it�s the slower powders that give you the highest velocities (H110/296 etc). This is true regardless of barrel length.
With rifles, you can�t make such a statement, because not always is it the slowest powder that gives you the highest velocities. But suffice to say, whatever powder gives you the best velocity in a 24� barrel, is probably going to be the one that gives you the highest velocity in a 16� barrel.
However, whether we�re talking revolver or rifle, that increased velocity in short barrels often comes at the expense of greatly increased noise and muzzle blast; which is not always desirable for this shooter.
