"what kind of game can .308 kill at 200-300?"
I was hunting moose with a friend carrying a 308 (Win 88 with open sights). I had a Win 358. We were in thick bush and expected to shoot moose at 25 to 50 yards. As we crossed a logging cut, we saw a moose walking across the cut at the far end. We were alter able to determine the distance was 425 yards.
I am an experienced shooter - he is an experienced hunter, but had never shot at a target beyond 100 yards. I shouted "Aim high!" We both fired 4 shots as the moose walked leisurly accros the cut, turned around and then walked back the way he had come from.
Becasue of mud and slash on the cut over, it took awhile to make it to where the moose had crossed. We were both surprised to find a dead moose.
It had been shot through the lungs twice. One shot from each side. I had aimed about 3 feet above its back and the assumption was that it was me that had done the deed. We could not find any of the bullets.
When I got home and checked the 358 bullet drop at 425 yards I became suspicious that unless my bullet bounced into the moose, it was not me that hit it.
later the butcher gave my buddy a recovered bullet. It was a 180 gr 308 bullet.
It was almost unmarked, except for rifling marks and a small dent on one side of the pointed lead nose.
My take on this is that becasue we were so far away the moose did not spook when we fired and even when he got hit. He laid down and bled out from the lung shots.
The total lack of tissue damage and bullet expansion at 400 yards leads me to say that although under the right circumstances one can hit a big animal, the sporting maximum distance is more like 300 yards.
Mario shot the moose from the standing position. He "Aimed high" but does not recall exactly how high. whatever it was, it was just right.
I have often hunted from a seated position over a log or big rock and could easily make an accurate shot at 400, maybe even 500 yards, but I don't regard the 308 Win as having enough power. Not only should a sportsman look for a clean kill, anyone who has ever dragged a moose out of the bush knows that the last thing you want is the moose to run out of the clearing into the deep bush.
I have other rifles more suitable if I was planning such a shot - say my 300 Win Mag or my 7 Rem mag.
This is why I suggest 200 to 300 is about max for the 308 Win.