Another welcome from Arizona. We in the southern central desert areas just can't seem to get rid of summer temperatures. Here it is 5 November & we're looking at predicted daytime highs in the low nineties!
.54 calibre is also my favourite & the GPR & GPH are excellent firearms. I've always preferred their design, balance & reliable accuracy. With numerous recommendations from forum members, I was able to devise a paper cartridge method that will greatly minimise my loading time. Coning the muzzle helped some too. I'm confident you'll discover everyone here is a pleasure to know even in a virtual sense. The forum is also very well-managed, so you've definitely come to the right place regarding muzzeloaders & even a few sidebars for good measure.