One rifle I've always liked is the US M1841 "Mississippi" Rifle. It's one if the handsomest US martial firearms and saw service in the Mexican War, on the frontier, and in the American Civil War.
During the 1840s and 1850s, the US government sold many M1841 rifles to pioneers heading west. It was a robust, powerful, and reliable rifle well suited for frontier service.
I ordered a Pedersoli replica in .54 caliber from Dixie Gun Works on Sunday and received it this morning. (I splurged for UPS next day shipping to minimize the chance of shenanigans during transit.)
The .54 caliber barrel is 33" long with a 1:48 rifling twist, with 7 grooves. According to Dixie the grooves are .006" deep. On my bathroom scale it weighs 9.3 lbs.
Dixie packaged the rifle nicely. Upon receipt I had to run a bunch of patches down the bore to remove whatever preservative crud Pedersoli applied. I also removed the lock for inspection, and hosed it out with oil, then blew out the excess with compressed air.
A close inspection didn't reveal any flaws, except that the rear sight was not centered. I used a Wyoming Sight Drifter tool to push it over to the left before my first range trip.
From what I've read and seen in videos on the "capandball" YouTube channel, the original service load was a patched .525" ball over 75 grains of "rifle" powder, i.e., FFFg. I decided to start with a slightly larger .526" ball over 80 grains of Goex FFg, with a 0.018" patch and Hoppe's No.9 Plus for lube.
In my gun this is a fairly tight combination. Shooting at an 8" bull from the bench at 50 yards my group was a couple inches high and right, with most of my shots in a 2" to 3" group. I'm sure with some load development and practice I'll be able to shrink this.
Pedersoli actually recommends a patched .530" ball, which would've required a mallet to start.
I was able to get my second group centered with a couple more whacks on the rear side with the Wyoming Sight Drifter.
My final two shots of the day were taken offhand at a ~16" steel plate, offhand at 50 yards, getting two hits. The big .526" ball makes a satisfying CLANG when it connects.
Ignition was provided by Scheutzen musket caps, which are very hot. I shoot left handed so my support (right) hand was unpleasantly splattered. I also have a 1984-vintage Euroarms Zouave which did the same thing, so I changed the nipple to one that takes No.11 caps.
After I got home I put in an order with Track of the Wolf for some .520" balls, .010" and .015" patching, and a nipple to take No.11 caps.
I'm also waiting for a package from S&S Firearms with a Mississippi Rifle shooting pouch and sling. That should arrive tomorrow.
Now that I have some hands-on with it I can see why the Mississippi Rifle was popular with troops, and also among civilians on the mid-19th Century frontier.