During years of Revolutionary War re-ennacting we used paper cartridge blanks. Usually around 100gr. FFg.
SOP is to set the cock at half-cock, tear the cartridge w/your teeth, prime the pan, close the frizzen, dump the rest down the muzzle (ram the rest down the bore if NOT in a mock battle situation), go to full-cock, aim, fire.
Nary a problem. Even the FFg as priming worked fine. (Admittedly with a bigger lock/pan/flint than a typical sporting rifle.)
P.S. I know, it sounds dangerous. That method of priming is historically accurate. During 10+ yrs. of doing it, in closed ranks and open order, 1000's of shots, I never witnessed or heard of an accidental discharge attributed to that method. However I would not reccomend it outside of that venue. Just a little anecdotal info.
