I was getting ready to ask about which 158 XTP.
You answered the question. Looks like the 158 XTP-HP did just fine at 1500 fps. Expansion looked about perfect.

A 1 mile pack out would be a real job. Waaaay back in the days before my first 4 wheeler. I tracked a wounded buck the father in law shot on opening morning. He had to head in to the lumber yard to go to work, and left it with me. I finished him off down by the river. I did have a logging road back up the hill to the pasture, but it was way to muddy to drive down. I was in my 20's and was still worried about a heart attack.

Great job by the way. The 6" GP100 is a very good revolver. I benched mine a while back with some heavy loaded 180 lead bullets for Bowling Pins. It was way more accurate than I had ever hoped for.

With A Jack Weigand Base, and a 30mm UltraDot no telling how well it would shoot. Lots of good things about a 357 Magnum. Reasonably cheap to practice with is high on the list. Mild Recoiling. Good bullets to reload with that are way cheaper than the bigger stuff. You might play with some 300MP or H110 powder. You should be able to get the velocity you are looking for with a little experimentation.

Keep up the good work. Good write up also.

Bob