I think you are talking about he SSB 375 grain?
I shoot them in my thunder hawk 50 cal.using 85 grains if triple777 from the bench at 100 yards 3 shots in a 1" hole
I also tried from the bench 200 yards they shoot about 17" low but a excellent group 4" with 5 rounds
I hit a doe with one a few years back she took 2 steps