There is a match, 'Class 3 Benchrest' which is basically unlimited class muzzleloading. The top competitors in past decades used fat round barrels, underhammer locks, and long cast boolits rather than RB or minies. The boolits are hammered down the bore. Three occasions that I have heard reported, the charge has gone off while ramming. The last of those was on a practice day before the 2013 Nationals, held at my location. The ramrod made an infinity-shaped hole in the roof over the firing point, and the thumb of the shooter was successfully re-attached.