Ive done 150's, 180's and 165's. I shoot a Rem 700 bdl. What I've learned is that my rifle likes the 165's. Ive also learned to not to split hairs. Its a white tail deer. Tough shots do come up but whats more important than bullet weight is shot placement. I put 80 shells thru prior to the season. Different yards and angles. And sometimes I really wish I was hunting with a shotgun!