Please use only real BP - the phony powders, Pyro and T series along with Black Mag 3 & I think the Shokey stuff are composed of 17% of the chemical that made corrosive primers, corrosive - potassium chlorate, ie: percholates. th is stuff makes pits, then excavates them with firing pulses. You might get away with it for a while - then maybe not.
I'd definitely NOT use it in any antique.