Rey, I think my buddy also used a FA bullet but I'm not positive & I didn't get to call him today, we were in Salt Lake at the Cancer center all day, got home late.
Not wanting to hi-jack this great thread but did want to mention that a good buddy of mine who has since passed away shot a Bison with my Ruger SRH about 15 years ago using one of my 370 gr cast bullets from a Ballisticast Mold that was about a 15 BHN. I think the load was 20 or 21 grs of 4227 so about 1000 to 1075 fps, some where in that range (guessing) The distance was about 20 yds as it was just a harvest bull about 2 years old. He shot it in the head, face on & Ron, the guy with him said it's hind legs kicked the belly so fast you could hardly see it.
Ron has also passed away & he also handgunned a bull but I don't remember the details. They didn't recover either bullet but had 2 bull Bison with 2 shots. This was west of Dillon, Montana.
I think if the bullet had been going faster it might have failed, just my thoughts.

Dick