Went shooting with my father the other day and he has a Pedersoli John Bodin rolling block rifle that has a 1 in 18 twist. He was shootin a black powder load ( triple 7) with a 405 gr bullet. @ 100 yards this load was key holling and the rounds were entering the target sideways ( could see a VERY clear cut out of the round). Did a lil research and from what I am seeing others are talking about the 405 gr bullets not being a good one for that rate of twist and to use a heavier bullet like the 500. Also found some "math equation" that seemed to agree with that. I was wondering if anyone here could also shead some light on to this situation. I know that the 405 round was the round the calvarey used for many years but further research lead me to find that the 405 were giving them issues in the longer barrels and that it was actually used in the shorter carbines. Please if any one here can help with this issue i would be trully appreciative.