2 groups come to mind. The first time I tried BM3 with a 460NE shot a 12+" group at 25 yards, didn't try 100. Another group was an experiment with a 54 Bobcat using 50cal REAL 320's in a .022" patch, I hit the 18" target 2 out of 5 shots at 15 yards, then gave up, bad idea.

At 100 yards with a good bullet and load not tweeked maybe 6" to 8". With a good bullet and tweeked load the best was about .5" for 5 shots.