Like the rest, I don't know anything about it except I found the barrel twist and caliber on the web.
Based on the twist I would say I agree that it is intended for bullets or sabots.
I also saw some stuff about it using Musket caps but from the picture you posted it looks like that nipple is for a standard #11 cap.
I can say with great assurance that if this rifle will shoot the pelleted powders, it will shoot loose powder even better.
Because the pelleted powders are synthetic black powder they all are harder to ignite than real black powder so I can also say that of all of the loose powders, real black powder fires best with the least delay.
Black powder is not more difficult to clean than the other powders, soap and water being all that is required.
Because of the fast twist I'm betting the rifling grooves are quite shallow. If so, that may make shooting patched roundballs an iffie proposition.
IMO, they would shoot best with a very tight ball/patch combination like a .495 diameter pure lead roundball and a .018-.020 thick cotton patch.
I mention round balls not just because they are the traditional projectile but because shooting them is quite inexpensive.
For 100 .490 or .495 diameter roundballs expect to pay about $10-$12.
You can make your own patches from some fairly thick 100 percent pure cotton cloth and $4 worth of it will easily make well over 100 patches.
If you decide to try this, look for the blue and white or red and white striped material called "Pillow ticking". It's great stuff for patches.
The roundball throughout history has been proven over and over to be an excellent hunting round if the range is kept to about 120 yards max.
If this gun is like some of the kind we don't talk about on this forum (In-Lines), it will be made to withstand powder charges up to about 120 grains. It might even take a 150 grain powder charge but ever muzzleloader I've seen (which includes some of the modern ones) will shoot much more accurately with smaller powder charges.
As for the power of smaller powder charges used with bullets one only has to think of the Military cartridge that was used for about 25 years, the venerable .45-70. That cartridge used 70 grains of powder and was more than respectable.
Speaking of powder charges I would recommend that you start with a powder load of about 50 grains.
Take a few shots, switch targets and up the load to 60 grains. Repeat this, noting the accuracy.
At some point the groups will start opening up.
When they do, keep increasing the powder load and shooting. Sometimes the groups will improve and sometimes they will get worse but you will only know by trying them.
Again, welcome aboard and post often.
