Nice rifle, Felix,
It is fun to shoot. When loading, I always feel like I am missing a step it is so fast. The beeswax and crisco or beeswax and tallow lubrication is the trick to keeping the rifle firing without jamming. Immerse the plug in the melted mixture and let it sit for a few minutes with heat still under the wax mixture. Then before the wax congeals, screw the warm plug into the gun which will spread a thin coat of wax on all the threads. The other trick is to avoid spilling loose powder in the threads above the chamber while loading. The threads are tapered and it is those top threads that make the seal and are most affected by powder fouling. I personally get off about 30 rounds without the screw plug needing any cleaning. Others, like Bryan Brown and Ricky Roberts claim to shoot 60-70 rounds without cleaning. I think condition such as cold and humidity effect those results. Also Felix, I use Swiss 3F powder, which burns hot and powerful. The powder chamber behind a 0.648 caliber ball can only take 50-55 grains of powder so I use the best, most powerful stuff. Bryan Brown suggests the proper ball historically is the standard 0.615 carbine round and I accept that as likely. Unfortunately, I can get no accuracy at all with that small a ball. I have yet to try something between a 0.648 and 0.615 but I have fine accuracy with the 0.648. Eventually, I am going to bore out the powder chamber to the same dimensions shown in Ferguson's patent so I can load 60-65 grains of powder that remain loose in the chamber.
dave