Yesterday I shot my Euroarms Remington 1863 "Zouave" rifle with replicas of the Williams cleaner bullet and some Lyman 575213 Minie balls.
My rifle was made in 1986 and I traded into it two years ago.
The original nipple took musket caps as you'd expect on a military rifle, but I found that as a left handed shooter, my right forearm and hand got peppered with debris. That was extremely unpleasant. I put a nipple that takes No.11 caps on it, which still gives reliable ignition but without the annoying spray on my arm.
The Williams cleaner bullets I have came from Gimcrack & Bunkum, a one man shop located in Pennsylvania. They are replicas of those issued during the Civil War. Unlike the Minie balls, they have a disc on a post that's attached to the base of the bullet. The disc expands into the rifling and scrapes out the fouling. These are 487 grains and .574" in diameter. I found them to shoot to about the same point of impact as the Lyman 575213 Minies, which weigh 510 grains, when both were fired over 60 grains of 2Fg Goex. I got the Minies from Track of the Wolf.
Some of my shots showed that the base separated from the body of the bullet and impacted elsewhere on the target. At 50 yards they broke the paper but not the plastic target backer.
When I bought the Williams bullets I chose to get them pre-lubed. The gap between the bottom disc and the base of the bullet has to be lube-free for it to work properly. The Minie was lubed by me a couple years ago with something, I forget what.
Offhand accuracy with this rifle is challenging due to a heavy trigger, probably around 10 lbs. I've considered taking the Zouave out for Pennsylvania's early antlerless-only season in October. I'll be hunting from a blind and will be able to shoot from a rest. But I'll probably use just a .54 caliber Investarm Bridger Hawken which has a nice trigger and is easier to shoot well.
Aside from the conicals I brought some .562" round balls, which shoot well in the rifle. However, I forgot my short starter so I stuck with the Williams and Minie bullets.