I have a real love hate relationship with the .62 caliber smoothbore. I have the same GMB that Roundball has in percussion. I have tried countless different loads, manner of loads, wads and no wads, just about any way you could think of shooting it. The best day I had on the range was the day I shot that group there. That was at 43 steps that I later shot/measured with a range finder to find it was 39 yards. After that distance I do not trust the rifle for accuracy. I did try shooting it once at 75 yards and actually missed the paper the target was on. Where it hit, I have no idea. The second shot I managed to get on paper in a corner. And also managed to fling one ball downrange and actually make a good hit. But that was because it was spraying all over the place.
For a shotgun, I load 80 grains of Goex and then push a Winchester AA plastic wad and then load 100 grains of #5 shot. It will really shoot with that and would be more then enough for 25-30yard shots on about anything I wanted to hunt. I was rolling a paint can around the yard one day and was surprised it would penetrate that paint can. I figured a bird had no chance at all.
The top picture was some penetration tests I was shooting. I shot all the way through that chunk of Balsam length wise. Also I recovered a ball that had hit the steel bullet trap. The splatter effect was really impressive. I think that would have been an excellent short range deer load. I just never would trust the rifle past 40 yards.
Like Roundball said, the versatility of the rifle was a reason it was so popular with early settlers. They could big game/small game hunt, bird hunt, basically hunt anything they could get close to, all with the same gun. Early settlers were not gun rich from what I read. They were lucky to own anything. Actually a lot of old military muskets were popular with early settlers because of their cost. Rifles were expensive actually, probably since most were individually made.
.62cal GM Flint Smoothbore barrels
so if you even think you might want one, you "better git while the gittin's good !"
