I know I've asked before ....

[Cold Spring]

PB, 7625 and 4756 are/were single-base straight nitrocellulose powders and imo there are no substitutes for their desirable combination of relatively low pressure @ relatively high velocity, and with a slower recoil impulse @ the same velocity and with the same shot load than double-base powders that contain NG. There's more to it than burning rate. Also, so-called low pressure loads often equate to low velocity which is OK on a clays course but all too often means cripples when hunting. Personally I look for at least 1225 fps for hunting, and 1250 or more is better and I'll load one of the named single-base powders for hunting with vintage SXS's that are up to snuff.

It seems that 4756 and 7625 went out of vogue with modern reloaders and can still be found in out of the way gun stores where the jugs are often gathering dust. I understand that PB is still made, although tough to find.