NTG,
I don't remember the specific brand of bullet, but do remember it's some common 55-grain cup-and-core. As noted, he primarily wants to make sure the bullet doesn't exit.
Might also note that a dozen years ago I went to Africa on a month-long cull hunt with a dozen other guys. One of the professional hunters took me and a friend out one day, allowing us to use his personal culling rifle, an old Sako .22-250. At that point it was on its 4th barrel and had taken around 12,000 springbok, a delicious antelope about the size of pronghorns. His favorite culling load is the Winchester factory 55-grain soft-point--which he gets wholesale because he also owns a big sporting goods store.
Anyway, we mostly were shooting springboks, and the rifle and load worked great out to 500 yards, which is as far as we ever shot. We were switching off on the rifle, and when it was my buddy's turn to shoot we came across an injured kudu bull, and the PH told my buddy to shoot it. He did, through the heart because the kudu had started to take off. It went went about 75 yards before stopping and dropping. Maybe it wouldn't have gone that far if shot with a bigger round, but I've seen more than one kudu bull go 60-100 when shot with the .375 H&H--and they're not considered among the tougher of the elk-sized plains game animals.
Funny how a hole through the heart or airbags ends life whether from a .22, .375 or a broadhead tipped arrow.
