High power rifle matches are fired in standing, sitting or kneeling and prone positions with the rifle held against ones shoulder without any artificial support. They use a sling in all positions except standing. They shoot both slow and rapid fire matches at 100, 200, 300, 500 and 600 yards; slow fire only at 800, 900 and 1000 yards. All with the same cartridge if they choose the .308 Win.
Benchrest matches are fired with the rifle resting atop something (that's artificial support) and is virtually untouched by humans except for a finger on their light-pull trigger. They shoot at similar ranges, but not with the same cartridge.
I wasn't comparing benchrest competition to hunting situations, now was I? That aside, some precision long range hunters take a portable table up in the mountains and shoot benchrest style at animals way over 1000 yards away with someone spotting their shots to tell them how much correction to make until the animal's nailed.
Thirty-ought-sixes are nowadays because of one minor change to the chamber dimensions. But back when the .308 took over in matches for a long time using typical field hunting positions, they were different.