I have an 1851 Pietta Marshall .44. They don't call it stainless anymore.
Mine's at least 10 years old? No rust yet. Fired it each evening after hunting Eastern Wa whitetail (muzzle loading season this week).
I forgot how powerful and accurate this gun is.
Basically, you fill the cylinder up to just enough room to fit the ball, less if you use a powder wad. Mine is a pretty hard press on the lever to seat .454 round balls, leaves a thin lead ring. I use Goex fffg, and cover the balls in bore butter, crisco, or wonderlube.
Also the cylinder axle.
I rate this gun tops! Cool looking, handy, powerful, accurate, what's not to like?
Cabelas has them on sale, I'm thinking about getting a second one.
I think the full cylinder is 30 grains under a ball. I used a 20 gr charger, and added about half again to each hole, then checked them all to make sure they were equal.
Leave one empty, under the hammer when carried, like in your holster while hunting with your Hawkin.