Most reenactors who fire blank loads load with loose powder only for rifles/muskets. In a typical gun the bang is plenty loud enough [tho' some use relatively large charges to increase the noise, I find mild loads amply loud]. For cannon, however, we load foil "cartridges" which are loud and which do send out small projectiles of foil and powder granules, as well as a pretty long flame--thus noone is allowed within 50 yds of the bore.