Dry-balling sucks! I'll tell you something else that does, too...
I was at the range one day with my friend Steve, and the range was rather busy, especially with muzzleloader hunters who were either new to the sport or were in a rush to get sighted in. I was shooting my Remington 700 MLS and had just finished swabbing the bore after a shot and had dropped in two fresh 50-grain Pyrodex pellets. The guy next to me was having some sort of difficulty, so I put down my rifle and went over to assist him, since I was "experienced" in muzzleloading.
After ten minutes of shaking my head at this rube's foolishness (don't ask me what the exact problem was, but it was enough that he eventually had to pack up and leave), I went back to my spot at the bench. I "knew" that I had just swabbed the bore, so I loaded two 50-grain Pyrodex pellets, rammed down a 295-grain Powerbelt Aerotip and capped the nipple. Placing the gun on Safe, I sighted in on the 100-yard target, pushed the safety to Fire, and squeezed off the shot.
BOOM!!! The recoil of 200 grains of Pyrodex pellets physically blew me off the bench seat! The bullet completely missed the target, my shoulder was throbbing (along with my butt, which landed on concrete), and I had (luckily) just the nearest hint of Weatherby eye.
After I got home I contacted Remington and they told me not to worry, as they proof with at least 300-grain loads (double 150-grain charges) "just in case." But I learned a valuable lesson: don't put a muzzleloader down halfway through loading and come back to it without checking everything out again.