RE: BP guns blowing up?
As long as you have people who think that they can take up muzzleloading for the extended hunting season and expect that they can get their ML to shoot like their .270 with minimum effort and minimum knowledge of what they are doing, MLs will continue to go Kaboom.
I know people like this. They buy a muzzleloader, look at the loading chart. and proceed to start with 150 gr of pyrodex with a heavy slug right off the bat. They shoot 3 or 4 shots to sight in and are ready to hunt. Darwin would be proud.