Well, it shoots... I shot it off the bench at my club range today just to get a feel for it. I only shot out to 50 yards, just trying to get it on paper. I was using what is known as a "half charge", or half the powder that would be used in a hunting load. This is the traditional way to sight in a round ball shooting muzzle loader - shoot to the sights with a half charge at 50 yards, and it will be zeroed at roughly 125 yards with a full charge.
So, today, it was 70 grains of Swiss 1.5Fg black powder with a .535" diameter round ball and a .015" thick patch lubed with Wonder Lube. With rifles meant for the patched round ball, we have a number of options on ball diameter, patch thickness, patch material, and lube. .54's usually use .530" or .535" diameter round balls. Patches typically run .010", .015", .018", .020", and .022" thick, and are made from cotton, pillow ticking, Irish linen, denim, and other natural fibers (we can't use modern synthetics, they melt).
Choice of ball diameter and patch thickness will obviously have a great deal of influence on how tight of a fit they are going down the bore. Match competitors like really tight combinations, hunters like them a bit easier to load down a fouled bore. Rifling depth plays a part in patch selection, with deeper rifling requiring thicker patches. This is something we play with until we find a combination our rifle likes, and one we don't mind loading. Too tight, or requiring wiping between every shot, just gets old. We look for a place where both of us are happy, rifle and rifleman.
I'm happy to say that this randomly chosen combination (on hand because I use it in the other two rifles) shot quite well, and was easy to load. 26 rounds fired without ever wiping the bore, with the last ball going down as easy as the first one. I like that. The lube I'm using, a grease known as "Wonder Lube", helps a great deal in this, by keeping the fouling soft.
It started out over a foot low, which it should, so that we can file down the front sight to bring the point of impact up (who says fixed sights aren't adjustable?). I fired several three shot groups, filing the front sight down .020" at first, then .010" as I got closer in between shooting those groups, slowly bringing the point of impact up. Here are the last two groups. The lower, three shot group was the second to last fired, after which I filed about .010" more off the front sight. The five shot group was the last one of the day, hitting at the elevation I want at 50 Yards (I was using a 6:00 hold, fudging into the black just a wee little bit). I fired five on the final group "just to be sure" and, well, because I was having so much fun. This is about as good as my uncorrected 62 year old eyeballs can do with open sights these days, so I'm pretty darn happy.
Next up, I'll be trying a full hunting charge of 140 grains at 100 yards. It should impact about 3" high, putting it right on at about 125-130 yards, and about 4"-5" low at 150 yards, then about two feet low at 200. So, in practical terms, we wind up with about a 150 yard "point blank" range for deer and elk hunting. I didn't want to go out to 100 yards today, since we are experiencing some pretty high, gusty winds. I'll wait for a calmer day for that. For now, though, I'm pretty darn happy.