Thread: Short barrels and full powder burn?

^

Depends what you are trying to accomplish. If you want to reduce the muzzle pressure to go a little bit easier on your suppressor and your ears, then a faster powder can make a small difference, sure. But if you are trying to attain the maximum possible velocity, then the slower powders will still give you that. They may be less efficient (in terms of chemical energy of the powder converted to kinetic energy imparted to the bullet) but it is more than offset by the larger charge weights used. The bullet gets driven harder for longer, giving more speed.

The best way to get speed safely, regardless of barrel length, is to jam the case full with the slowest stuff reasonably possible and blow a healthy portion of it out the end of the barrel "unburned".