I have had less than desirable results with 165gn factory rounds. Two years ago, my first time ever using them, a round penciled between to ribs on a BIG, full-rut whitetail buck (weighed 218 lbs when I hung him up) failed to expand, went through both lungs (again a pencil), hit the offside shoulder and THEN did it's job! Smashed through that shoulder, shrapnel blew back and liquified that offside lung. That buck took 4hours to die with me standing there well after dark with no rifle watching it expire for 20' away. That was a 360yd shot from an M77 Ruger in .30-06. Zero complaints with accuracy, bullet went exactly where it was supposed to, just did not do what it was supposed to do.
last year, circumstances in my home and life kept me from shooting. I had purchased a new rifle, built work-rounds, but was never able to fire any. So, I used that Ruger again. Again, 165gn CoreLokts. 240 yds at a cow moose. First round downrange is a sad story for another time, but the second, again, was right on. But did NOTHING except cause her to swap ends and continue feeding. My buddy dropped her with a .270 WSSM 10 minutes later from the other side of the cut when I told him she was heading that way, SLOWLY, UN-CONCERNED, with the rest of her family group (yeah, that's right, I watched 5 moose for 10 minutes without taking another shot). Unfortunately, other than a hole in a rib, I can't guarantee anything else happened, since there was an entrance hole on the opposite side, nothing left inside (lungs and heart were gone) a huge exit hole, with my little entrance hole just 3/4" higher than his exit. She simply fell down.
I bought that M77 and got 5 boxes of rounds with it, some partial. 2x150 gn, 2x 165gn, 1x180gn. It had been shooting 165s, the guy told me, but after 20 years, the rifle didn't seem to be getting the job done, so he bought another in 300WM. I haven't fired a single round in 150 or 180gn, but I have fired the remaining half a box of 165s for zero verification and two at game. Lots of older guys SWORE by CoreLokts when I was growing up, I used reloads. Someone can have these if you're close or I'm pulling them and tossing them out. Accurate as hell, I just can't trust them at all.
Just my experience.