Go back for one more session. I do not know your experience level so I am going to go back to basics. Lay your ammo out on a towel in the shade. Let them normalize. Get everything set up and ready to fire. Place one round in the mag and insert it into the mag well with bolt open. Get your sights close. Bipod relaxed, hand relaxed, finger in the correct position opposite hand under the butt. Butt lightly pulled into your shoulder. Repeat everything the exact same way every time. Correct you position if needed, I shoot better if my shoulders are somewhat square to the target. Drop the bolt and fire without getting into a hurry.

Release the mag and put another cartridge in the mag. Repeat the rest of the steps and fire. Feel the barrel. Make note. Continue this for your group count. Remember to not chamber the cartridge until you are ready to shoot. If the chamber is hot it will change the pressure. Do not let the barrel get too hot to touch when you are shooting for groups. Try to maintain barrel temperature within a reasonable range. Do not let a cartridge sit in a hot chamber when shooting for groups. If you must, pull it out and put a cooler one in.

Good luck.