[Drdogface]

I don't know how well this following method works with smokeless powder but I used to reload Black Powder blanks this way for Cowboy fast draw competition. Take an empty case and cut discs out of a styrofoam paper plate...make sure all discs are complete with no notches in the perimeter. Prime your cases and add, say, 2 gr of whatever smokeless powder you choose and seal it with a styrofoam disc. The foam should burn or just blow apart upon firing but always fire up in the air anyway.

I used either real BP or a BP substitute like Triple Seven and loaded about 1/3 of a case of powder. Makes a nice big boom. The Triple Seven residue is easy to clean out of the pistol with Green Windex or mild soapy water. It should work fine for your purpose.