Whatever you have the most confidence in and shoot accurately should be considered in your choice. If your 6.5 prc meets theseI have been told that my 6.5 PRC is too light for elk and I am sure many of you on here will agree. But I when I look at the ballistics, my 156gr Berger with H1000 have more energy and velocity after 400yds than my buddy's 300wm with 180gr ABs. which is an acceptable elk cartridge. Since hunting bullets are made to expand why is initial bullet size important?
requirements and you are confident you can make the shot then that is what you should use.