I personally have never killed an elk with a .264" diameter bullet, but I have seen it done quite a few times.
Cartridges were;
6.5 Swede. -- 9 times Most were good kills with 2 being not so good. Bullets used were from 123 to 160 grains. The "not so good ones" were thinly jacketed 140s and one time with 123 grain bullets.
264 Win Mag -- 1 time. Winchester 140 grain factory load. Seemed fine.
260 Remington. -- 5 times. 4 different hunters with 3 having very good results and 2 having bad experience with bullet that shattered and didn't penetrate well. Bullets from 130 to 160 grains. All the bad ones were "super accurate" but just didn't hold together.
6.5/06 -- 2 times. One good kill and one poor kill that took 2 shots both hitting the back end of the lungs and we still had to track it for about 1/4 mile.

All did fine when mated with bullet that hold together, but the only bullets I have seen used that gave exits wounds all fired Barnes X or 140 grain Partitions. Even they don't exit about 1/2 the time, so placement is important because if the elk doesn't drop fast you may be in for a challenging tracking job, if you have no exit wound to leave a good blood trail. Hit right with 6.5s the elk don't go far.

If you were going to use a 6.5 PRC for elk I would say Solid Expanding types are what you'd want to look at pretty hard.

T. Inman said it best;
Bullet construction can be a bit contentious in associated conversations, but the caliber generally is not.

Using good hunting bullets instead of "target bullets' I would hunt with a 6.5 with no great concern. I have not done that yet, but tit doesn't mean I would not. As of now I only own one 6.5, and it's the old 1903 6.5X54 M/S. Yet with the 156 and 160 grain bullets I choose to mate it with, I would not even hesitate to kill elk with it. Renowned hunters from about 1904 clear through the 1940s used it and said a lot of good things about it, so a 6.5PRC is going to do everything the old Mannlicjer will do and more. Just don't shoot bullets that break up because they are "more accurate" . Elk are not small.

More deadly is WAAAAAAAAAAAY more important then more accurate.

Last edited by szihn; 09/23/20.