The 125 grain, 30-06 factory rounds I've fired were all too lightly jacketed for Maine deer or tougher game animals. I used a lot of handloaded 125 grain loads for woodchuck hunting and they worked well, opening adequately on those relatively small, but tough critters. For larger critters, 150, 165, and 180 grain projectiles opened adequately on deer and bear-sized game, but it's best to test them on inanimate objects to assure adequate performance. I tended to use more 165 grain PSP bullets than anything else in my '06 deer handloads, giving fairly flat trajectory at medium to longer range, while providing adequate expansion.
For hunting at under 200 yards, flat trajectory doesn't matter as much as controlled expansion.
For hunting at under 200 yards, flat trajectory doesn't matter as much as controlled expansion.