Smokeless has about 4-5X the power of black powder so if you use the same amount of smokeless as you normally would for BP you will hurt yourself!! However if you pick a load consistent with the design of the gun, which looks to be around 4.5 grains of smokeless for a 44 cal cap & ball gun I don't see why it would not work. The light weigh-for-its-caliber ball and big mostly empty chamber keep the pressure down. I tried it and it worked for me, no damage to the gun or me. Of course you could easily double or triple load a chamber and not notice it. This could result in injury!!