Last year with my winchester .50 inline i was shooting 150 grains pyrodex RS with a 245 grain powerbelt hollow point, It was 7" high at 100 yards and dead on at 200. You'll probably want to stay in the 120-130 grain area with powder. 150 grains of loose powder is really just a waste and doesnt burn it all. Use a bullet in the 240-270 grain area so you dont have as much drop and recoil. If you are using open sights and plan on shooting a deer at 200 yards... good luck! They are hard to see at that distance. And if you are using a scope on that muzzleloader, Shame on you ya cheater! lol