I personally never saw a reason for the .308 to even exist. I always thought it was just a weak .30-'06. But I just bought a Tikka T3 Lite .308 and can't wait to get a scope on it. The .308 is nearly universal here in Europe for everything from roe deer to hogs to red deer, mufflon and chamois. I also have a 6mm Remington in the Ruger 77 Heavy Barrel that is a sweet shooting gun. I begged a buddy to sell it to me after he smoked a couple of deer with it one year in 'Bama. That is the one my wife shoots at deer. Way less kick that the '06 and less than my .308 too. It's the same relation to the .243 that the '06 is to the .308. Same bullet, just faster. If I moved up north where the deer are big I probably wouldn't choose that as my primary. In fact I have many rifles now that are better "all-around" choices that I probably won't hunt deer with it again. But then, the original question wasn't about an "all-around" rifle. For a young girl (and I have three teenagers) a heavy barreled .243 (or in my case 6mm) would be (and is) just fine. They will be hunting in controlled conditions with easy shots at feeding deer. All we have to do is wait for a good shot and make a gentle squeeze. That little 6mm pill will have them on the ground with 50 yards... Would my .308 (with any loading) kill them any faster with a heart/lung shot? Probably not. On other shots, yep, it'll have a better chance of dropping them quickly and humanely. When the kids graduate to hunting more on their own, they get to choose what they want to use. I'll advise them but they have to make that choice on their own. For my kids, I'll try to get them to stay with a mid-range round starting with a 6.5x55 and moving up to a '06 level. No need for more... I've shot deer with .223, 30-30, 6mm, '06, 44 mag, 45-70, .45 cal and 50 cal muzzleloaders and 12 and 20 gauge slugs. Not as many as some but enough to know that middle calibers at about 2400 to 3000 fps just do the job without too much fuss and muss. The bigger bullets and slugs do it just as well, they just hurt more on the shooting end too. No sense hurting the kids or wounding deer with iffy shots for little bullets.
ngh