RockMcL, Honestly, I would be happy with no expansion at all. "Back in the old days" we all shot Hawkens using heavy lead conicals. never saw much expansion, but they knocked a 50-caliber hole all the way through, no matter the angle. 50-caliber in, 50-caliber out, and massive blood trails and quick kills. Ever since we switched to in-lines and all the fancy bullets, we've had major problems with bullets expanding too fast or going to pieces, and no exit hole. Have nearly lost several deer because of no exit hole and no blood trail. I could always go back to conicals, but I HATE how hard they are to load, as you have to cut into the rifling at loading. I've really like the Powerbelts because they load easy, are actually 50 caliber instead of 45 in a sabot and are deadly accurate in our guns (multiple shots often punching a single hole at 75 yards). I just wish I could find a Powerbelt that doesn't expand as fast.
And as a reference, we're all shoot either 90 grains of FFFg or 90 grains of 777 with 209 primers. Shooting opportunities on deer beyond 75 yards are rare.