Gringo Loco,
The Interlock that didn't penetrate was a 117-grain .25 boattail from the .257 Roberts, muzzle velocity a little over 2900 fps. The animal was a mature mule deer doe, standing quartering toward us. My cousin was the hunter, and he put the bullet in the shoulder joint so it would angle through the chest. It would have if it hadn't come apart, but instead what was left of the jacket and core stopped in the ribcage.
The doe turned sideaway after the shot and started limping away, so he shot again, behind the shoulder, and that bullet went all the way through, putting the deer down.
The 250 roundnose Interlock is a good one in the .358 Winchester, though of course trajectory isn't very flat! I used to handload them for one of my hunting mentors for his Savage 99 after Winchester quit making 250 factory loads, and he liked the way they didn't shoot up meta and penetrated well. Among other animals he took a BIG 6x6 elk with them, but also a lot of eating-size deer. I inherited the rifle and used them as well, but Hornady eventually discontinued the round-nose, though I see them at gun shows now and then. I switched to 225 Partitions, which work very well.
