Shiloh Rifle Forums

Does anyone know of a published finding on how compression of black powder has an affect/effect on velocity and SD?

Glen,

I don't know about specific data, but I find that accuracy, velocity, and SD vary by rifle, powder lot, bullet, and whether the bullet is jumping or into the lands.

Clarence

I am finding that to be true Clarence. I only shoot Pyrodex and in my 40-65 the load it loves is compressed about 1/16th of an inch and with a hard bullet. ( Thanks for including that tip in your book Wayne ) My 45-70 does NOT like a compressed load of Pyrodex. Jeanne has ordered a new 40-65 so we'll see what it likes. I hope to see you at 100% and chasing the antelope off the range this summer.

I used Pyrodex and sub's for years. They all said. Do Not Compress. Remember, they are basically smokeless and pressure can bump up a lot.
I would stick to good ol' BP. more accurate, safer, and you have to clean with both of them anyway. No benefit to using sub's .
Only me.....Ken