[Jeff Higgins]

That's what used to be known as a "chunk gun". "Chunk" shooting was the predecessor to modern bench rest competition. Competitors lay prone behind a rest, often simply a log on the ground, and rest the muzzle on the log or "chunk". As the game evolved, many competitors fashioned their own rests that they brought with them to the matches. That's what the little bipod doohickey is. Chunk guns got pretty big in some classes, like up to 50-60 pounds or more, so yours is on the light end of the spectrum.

Early chunk guns all fired patched round ball, so there was little need for a false muzzle. The purpose of the false muzzle is not to protect the rifling, but to ensure an elongated "picket" bullet starts straight. The false muzzle is simply the end of the original barrel. In other words, the false muzzle and barrel start out as one piece and then get cut apart, with the four (sometimes only two) alignment pin holes drilled deep enough to go through what would become that false muzzle and into what would become the end of the barrel. Once the false muzzle portion was cut off, its rifling was reamed out and a slight taper added at the end through which the bullet was started.

Yours looks like about a 40-45 caliber, which was the common range of bore sizes once the bullet took over from the ball. With a matching mold, you have all the tools you need to shoot it. When casting bullets, best results are obtained with pure, soft lead. The bullet has to be soft enough in a muzzle loader to "bump up" as the old timers called it; it must obturate to fill the bore properly. If it was big enough to do that before you loaded it, you would never be able to ram it down the bore. They start out a wee bit undersized, and rely upon a good hard whack from the igniting powder to foreshorten them and bump them up.

Hopefully a powder measure was included; one that someone has already tailored to the rifle. If not, start out with lighter charges of black powder, like around 40-50 grains or so. Use what is known as "FFG" granulation, or "double F" as we call it. Black powder, unlike smokeless, is all the same chemically. Burning rate is controlled by grain size, and grain size is indicated by the number of "F's" - Fg, FFg, FFFg, FFFFg are the common grain sizes. The more "F's" the finer the powder and the faster burning. Fg is typically used in shotguns, FFg in 40 caliber and larger rifles, FFFg in small bore rifles, pistols, and revolvers, and FFFFg as a priming powder in the pan of flint locks.

Make sure the powder is well compressed when seating the bullet - really lean on the ramrod once you feel the bullet touch the powder. Any airspace between the two can damage the rifle. Lube the bullet (it should have grease grooves) with a good commercially available black powder specific lubricant. Thompson-Center Wonder Lube is a good one. Don't use a wad or anything between bullet and powder; just the plain lubed bullet.

Igniition is by means of a percussion cap that fits over the nipple. Backtracking just a bit, when you first prepare the gun to fire, you will wnat to swab all oil out of the bore and from under the nipple. You will never get the breech area completely dry that way, and if you don't, the gun will hang fire or miss fire. Snap a few caps on it before loading it to dry that area out completely. Caps come in a couple of sizes, #10 and #11 (plus a much larger military "musket" cap, which your rifle doesn't use). If you can, drop by the gun shop with the rifle in hand (or just the nipple) and see what fits.

These things need to be "cleaned" after every shot. I use one damp patch (with water) followed by one dry one. It's more just a cursory swabbing, to get the heavy powder fouling out. Neglect to do that, and the next bullet may get stuck in the bore when you are trying to load it. Don't ever try to shoot one out - if it's not fully seated on the powder charge, it will act like a bore obstruction and will damage the rifle. Perhaps catastrophically...

I clean up with a tight cleaning patch on a jag, submerging the breech end of the barrel in a pale of very hot water. The barrel separates from the stock by driving the wedge pin out, then either hinging it up out of a hooked style recess in the front of the tang, or by taking the two tang screws out if the barrel and tang are integral. Pump the cleaning rod up and down like a bicycle pump handle, drawing water in the barrel though the submerged nipple. Do that a few times, them remove the nipple and do it again. Dry the barrel and nipple, run a patch down bore with some Hoppe's #9 on it, wipe some all over the nipple and outside of the barrel, and you're done.

Anyway, there should be no reason not to shoot it. I would, however, have it examined by someone in the know. Sometimes the breech plug, which is threaded into the back of the barrel, can be a place rust will start. It starts in those threads, sometimes compromising their strength. A gunsmith should be able to unscrew it and look. If it checks out, by all means, shoot it. It's a lot of fun.