I have a repro Gallagher .54 made by Erma (West Germany). This is one of those guns that you either like or hate. I like mine alot. The barrel (reportedly made from German machine gun barrels) has a 1-18" twist. Most shooters say that you must use hard lead or you'll soon have a smoothbore. Alot of owners have them relined in .50. I've been shooting .535 roundballs in mine, and they shoot well out to about 50 yds, but after a two year search I recently bought a Rapine 540300 mold in good shape at a great price.
The brass cases ($2.25 each) are pretty much indestructible, They do not take a primer (ignition is via a musket cap on a nipple), and they do not have to be sized. You seat the bullet by hand (finger) so you can reload at the range. Closing the lever action seats the bullet deeper into the case.
I loaded up a batch of hard and soft lead with the Rapine mold (the roundballs I've been using are musket ball-soft). Using case capacity of 40 grs FFG, I can gong the gong at 100 yds just about every time (it takes about 5 minutes for the bullet to get there, though).
The key that I found to keeping the bore clean, shiny and shootable is the vegetable spray PAM (or a cheaper store version). I use a homemade paraffin/beeswax lube on the bullets, but before every shooting session I spray the PAM down the barrel, then again after every five or so shots, followed by a single cloth patch. After 35 rounds, the barrel is shiny and clean with no leading or build-up of any kind.
PAM has been very good to me.
Anyone else have one of these oddball beauties?
Shown with a Vetterli .41