The risk you take by using a thinner patch is the patch burning in the barrel, As it cannot hold enough lube to keep the flame from the powder from igniting the patch before it leaves the muzzle. The answer to that is one of the choice mentioned above, OR using an overpowder wad to seal the bore gases away from the patching and ball. I prefer the latter, as I think way too much is being asked of a cloth patch in most ML firearms. When I finally got a chronograph, and began playing with that new toy, as men are wont to do, I found out a lot about my ML rifle and smoothbore loads, and a lot of it was stuff I didn't want to know. My brother had sent me some wads, asking me to try them in my .50 cal. rifle. I did. Damn! The SDV dropped dramatically, and my velocity rose more than 100 fps. I have had to rethink everything I have done with a ML rifle or shotgun over the past 30 years, because that darn machine just won't " fudge " data for me. Worse, I am getting better accuracy, and I am eliminating some of my favorite " alibi's " I have always used to explain a wide shot! Darn. Darn. Darn! :cursing: I found the same thing working up loads in my new 20 ga. fowler. I am also messing with patch thickness, but I found early on that I get better velocity, and lower SDV in my fowler, if I use an overpowder wad, and then run the PRB down on top of it. Accuracy is greatly improved.
Its fun to just shoot these guns. But I found it even more fun to actually hit what I am shooting at, and at longer ranges. :surrender: