Thread: black powder data

Black powder charge weights are more of a question of how much would I like to compress this charge.

If you use the same volume of black powder you used for a light projectile for a heavier projectile you have a couple options. 1. reduce charge weight to account for greater volume of case being used up by the heavier (longer projectile) when seated to same over all length making the compression of the charge the same, 2. compress the original charge more by seating the heavier projectile to the same over all length, and 3. seat the projectile out further for a longer over all length but have the base of the projectile sitting at the same point in the case as the lighter projectile. Possible alternate option; remove filler, wads, or other, if used, to compensate for extra case volume used up by projectile. Ensuring in all circumstances you have 100% fill of case underneath the projectile.

Somewhere in this mixture of charge weight/volume, compression and seating depth is your most accurate load.

I use a powder compression die for 45-70 and compress to the point where only the last little bit of bullet seating touches and slightly compresses the charge. I also use just a card wad to try and prevent gas cutting of the base of the projectile (although I haven't tried without so it's precautionary, not responsive to a problem) nothing else other than well lubed projectiles.