RE: 200 gr.(black powder) bullet for mule deer
if it shoots that good use it and dont worry about it. A 200 grainer with 120 grains of trip seven behind it should have a muzzle velocity over 2000 fps thats as good as any 35 remington a very well known mule deer cartridge. you should easily have enough gun there for even a 200 yard shot. where will you be hunting? good luck hope you bag one.