If your 1851 is brass framed, do as Mulegunner suggested, and stay with 20 grains or less. I have two brass frame cap & ball revolvers. They are both .36 caliber. A Hawes 1851 Sheriff's model, and an F.I.E. 1858 Rem. I experimented until I knew exactly how much powder it took to seat the ball with a little compression, and cut a spout to throw that much powder. I think the amount was 17 grains. I have had them for over 30 years, and they have both burned several pounds of powder. Even with those light charges, they both show signs of excessive barrel/cylinder gap. Niether one of them has been shot nearly as much as the steel framed Uberti 1860 Army that is the same age, and that is as solid as the day I bought it in 1970. If yours is a steel frame, I would only load it with the max amount listed in the pamphlet that came in the box with your pistol. I don't know about the .44 1851, but The steel frame .44s I have (depending on maker) suggest from 26 to 30 grains of black powder. No matter how much you overload it, it will not be a magnum performer, and you will be loosening things up. I have an Army San Marco Walker that will hold about 60 grains of powder, but according to my conograph, I get roughly the same velocity with 40 grains, as I get when I fill it up. These cap & ball revolvers are made from pretty mild steel, so stay within, or better yet, a little under the suggested max. They are fun,but have limitations. On those occasions you feel you need more power, take one of your modern sixguns, which are designed to provide a higher performance.
