"During the first 2 days, he lost 2 deer, which he claims he hit but they ran away. The range both times was within 50 yards (according to him). We did find a little blood but not 1 of those deer. "
Everyone has stories of , or experienced themselves firsthand, lost game where some blood was found. I suspect either the shooter in your story missed, poor shot placement, or a combination with poor hunting skills thrown in the mix. Poking holes in deer and loosing them I suspect has little to do with the bullet performance. Even if the 30 cal bullets didn't expand any decent hit would result in a dead deer found with proper looking.
I have only killed 13 deer, and 2 were difficult to trail. Bullet performance is less important than bullet placement. I would try both style bullets and choose the more accurate one vs performance claims of said bullets. That said, I try Nosler partitions in my hunting rifles, and all have shot well enough. I have shot 3 deer since going away from Sierra and Hornady bullets, and have seen no difference, but I haven't really tested them by breaking major bone structure.
Good information stated above, plenty to help you choose which direction to lean towards. I do suggest the 165's for 308 velocities over the 180 , but you need to run the ballistics tables at 308 velocities to see which performs better. I was surprised at the 165 vs 180 Partition ballistics at 300 wby velocities.... 180 has an advantage for long shooting.
Allen
