Suggestions from a recoil wimp. If you send 2,000 foot pounds of energy down range, you are going to flinch. If you do it long enough you will/may someday control it. If you experience pain when you fire, your flinch will be extreme.
#1 Is there any real reason you have to do your range time with hot loads? Load down for range shooting. Zero your rifle with what you hunt with, but there is no reason you can not shoot softer loads for practice. If the point of impact is different with practice ammo, consider that when you evaluate your targets.
#2 Stance is important. If you are firing right handed, and are standing left side forward your body can not twist to absorb recoil. If you are close to face on to your target, your shoulder can yield, and your body twist to absorb recoil. Recoil is as much a matter of time as it is of power. If your body rotates it will accept more recoil than if it has to maintain position. We have all heard about someone shooting with their back against a tree or a rock.
#3 A bad flinch is your shoulder moving towards the gun, IMHO. If you do not have the gun held solidly against your shoulder the recoil is amplified many times. Make a fist, and hit your other palm with it hard from four inches away. Then make a fist, and touch your other palm and hit it as hard as you can and you will see the difference. When I am shooting a "recoil monster" something that helps me is to use four triggers. First, pull with your pinky on the pistol grip, then the third finger, then the second finger. Then pull the final trigger to fire. That seems to help me get the rifle pulled solidly back into my shoulder.
You will not notice the recoil when you fire at game and if you can stop the flinch on the range you will have the confidence to make the shot. My ultimate solution was to get a smaller caliber. If I ever get to hunt anything bigger than Kansas whitetails, I will have to deal with my "no pain is good" attitude, I suppose