This is a Connecticut Valley Arms .50 caliber Express Rifle.
From what I hear, the rifling is 1:48, so it is not suited to heavy charges under a roundball. Fast twist like this is likely to "strip" the rifling and cause terrible accuracy. I will have to see by progressively building larger and larger charges to see what comes of it. However, I have read some people have had better luck shooting saboted modern muzzleloading bullets, something I am loathe to do at this juncture.
I have also heard that the gun was not well "regulated", meaning the barrels are not set to converge at a set distance from the gun where the single set of sights can be adjusted. I guess I am not taking this gun to shooting competitions where the need to punch the center of the target is super critical....more likely I will be happy to be able to hit a pie plate sized target at 50 yards 10/10 with one or both barrels. This could be a happy little hunting gun for heavier cover if that were the case.
If not, I shall put on my pith helmet, monocle, grab up my trusty double rifle and pretend to be hunting hephalumps and tiggers in the darkest jungles of the world!