I hunted my bison with my T/C Black Diamond, and a .50 caliber FPB bullet over 100 grains of Triple 7. The shot was about 50 yards. I fired and the bull didn't flinch.
The guide asked me if I hit him. No sooner did he say this, the bull dropped in it's tracks. The guide laughed and said "For a minute, I thought you had forgotten to put a bullet in your gun!" His talk quickly turned to the fact that he had never seen anyone drop a bull bison in it's tracks with one shot.
My Thompson may not be the newest model on the market, but it did the job in true Thompson/Center fashion. I've taken many deer with it, and now a dream come true bison.
Thank you Thompson/Center