I Forgot. 1 in 48 is the twist rate.

I would say anywhere from 80-100 grns of 2F with that weight of bullet in a fifty cal. On a flinter there are a few little things that you should do each time you load and shoot it to be consistent and accurate for hunting. Another thing that is very important is the flint, the angle it strikes the frizzen and the sharpness of the flint. Make sure the flint is striking the frizzen in a raking motion from top to bottom. You can adjust this by changing the length of the flint in the jaws, placing the flat part of the flint either up or down to get the cutting edge of the flint cutting a good shower of sparks into the pan. Leather is a good material to place around the flint and into the hammer jaws to hold the flint in place. I have found that very thin sheet lead is better but it is hard to find. Cut you a piece of leather about 1/2" wide and 1 1/2" long, wrap the back of the flint with the leather on top and bottom of the flint and place in the jaws and tighten. This keeps the flint in place and add as a cushion when striking the frizzen to extend your flint life. To sharpen, while the flint is in the hammer, on half cock or full cock with the pan and barrel empty, tap the cutting edge of the flint with the back of a knife or small brass hammer striking down and into the cutting edge a little to flake small pieces of the flint to build a new sharp edge. This speeds your lock time in the ignition process some.
Load the same weight of powder each time. Try to place the same amount of pressure when setting the bullet with the loading rod. Make a mark on the rod so to get the same depth on the bullet in the barrel each time.
Make, borrow or buy a touch hole prick. Closer your frizzen onthe pan each time you place powder in the barrel. Before charging the pan, push a touch hole prick in to the hole several times, making sure you get a good hole into the powder charge in the barrel. When charging the pan, tilt the rifle towards you, (for right hand rifle)and place priming powder in the pan, rap the rifle with your hand to settle some priming powder into the touch hole and don'w fill your priming pan with too much powder. The priming powder in the pan should be level with the touch hole. If too much powder is use, this will slow your ignition to the powder in the barrel and cause undue flash in low light hunting situations.
With a flintlock make sure of your hold, and try to get a steady rest to allow you to hold during the lag in the lock time and priming powder going off. This is not as much an issue with custom rifles with very well tuned locks. I have flintlock rifles that are as fast as caplocks and there is no lag time as far as anyone can tell that shoots with me.
Enjoy and put one in the boiler room and the deer with not go anywhere.

Mike

Hold on fellas! No one ever said what rate of twist the rifling is! If it is a 1 in 60 for round balls, it would be a waste of time and money to try and shoot Power Belts. Please clarify this first.

He didn't say what twist his rifle was but I looked it up in the Cabela's shooting catalog I had so I wouldn't lead him a stray. The 1-60 twist barrels I use for some of my roundball rifles will shoot the Hornady Great Planins hollow base bullet very well with about 90grns of 2f in a 50 cal and 100 grns in a .54 and those are 36-38" barrels.
Don't think they would shoot a power belt.
Good luck Tweesdad with your hunting.

Mike

I have found 90 grains of FFg to be very accurate with the 295-grain Power Belt in my .50 cal.