What I would like to know going back to the original question and adding this... which twist rate will provide you the best hunting accuracy @100 yards or beyond?

50/75 yards is not a problem at all with a 1/48. But for myself, shooting a 1/48 going to 100 yards really opens the pattern up, especially when shot with what i would call a hunting load charge 80/90 grains in a 50 cal.

Another question... What size of group might an average shooter expect using open sights @ 100 yards with a PRB?