I need some help selecting a bullet for my .54 caliber Knight-MK-85 muzzleloader. I just switched over from black power to pyrodex pellets. I use 2 pellets which is 120 grains. At 50 yards I was able to easily get on target and get 1-2" groups however, when I moved back to 80 yds I could not even hit an 8.5 x 11 sheet of paper. I am shooting a pretty light bullet (250 grains) for a .54 caliber and I am wondering if this is my problem. Most of the information on line points to using 300+ grains. I am also having a problem finding bullets for a .54 caliber, any suggestions would be much appreciated. I would like to be sighted in out to 100 yards.