I was wondering if my Glock 21 barrel would work in my Glock 30. Perhaps the longer barrel might offer some ballistic advantages. Also, I've wondered if anyone has information on pistol caliber ballistics through various barrel lengths. It seems to me that my 2.25" .357 Magnum Ruger SP101 revolver wouldn't perform any better with a .357 Magnum cartridge than a .38 because the extra powder would simply burn up outside the short barrel. Does that make sense?