It breaks suspension of disbelief for you, but my players are arguing for having it only cost a supplemental. So, it obviously isn't a problem for them. It is for me, though, and I must find a middle ground. Granted, I should have hammered out rules for muskets BEFORE players made their characters, but I didn't and now I'm looking for a solution that is a compromise and is balanced.
I don't know your players, so I might be off base on this, but honestly, this seems to me as the player in question being less concerned about believability and more concerned about getting to use his preferred skill and most powerful available weapon as often as he can manage.
I mean, if someone comes at him with a sword or something, chances are he's going to be defending it
with the musket. How he's going to manage that
and a seven-step reloading process at the same time just boggles the mind. (Maybe if he had a shapeshifting power and gave himself a couple extra arms...hey, it worked for the T-1000.)
Lastly, this is a game and their characters are supposed to be exceptional and I want the players to have fun. Most of them are first-time RPGers, much less Dresden players. If I go all rules-lawyer on them and tell them "no" for everything, they won't want to play anymore.
I'm not saying you should say no to everything. Just to the things that don't make sense.
And he can still use guns as a primary weapon--a brace of pistols can be as nebulous a number as the amount of bullets in a clip, and in my experience combat rarely lasts more than 5 or 6 rounds, so it would be completely believable that he has enough pre-loaded pistols to last him through a scene of melee combat.
And even if he runs out of that, a musket is still five feet of solid wood (potentially with a pointy bit at one end), meaning he's still got a Weapon:2 or 3 to fall back on. To me, that's where the speed power would come in handy--not reloading (which is more precision and finesse than speed), but in fighting hand-to-hand.
It's actually the experienced player who's arguing for the quick re-loads, actually.
I'm sure he is, but I have to ask, is he an experienced
gamer or an experienced
roleplayer? And while I'm sure he's experienced in gaming, is he familiar with muskets?