I forgot about the 250 Savage. Great round that doesn't get enough credit. I suppose in the days of short mags and ultra mags there is no room left for the 250 Savage, 257 Roberts or even the 300 Savage.

11 year olds come in all sizes. He could weigh anywhere from 60 to 120 pounds. Makes a big difference.

I always think you can't skimp on the gun. You need to have a caliber that will do the job well. Hired pros can use some light calibers because they are precision marksmen. Most 11 year olds are at the beginner level.

243 is the smallest I'd go. If he's a bigger kid, then perhaps a 260, 270, 7-08, 7 x 57, or even a .308 if you handload. One of the newfangled recoil pads can do wonders.

The 250Savage may not be readily available, but how about the 257Roberts. It is very
mild also, and last I looked is still available in the Ruger77 or its' Ultra-Light version.
Then too, the 260Rem. should be mild to shoot as well. Especially when using the lighter
bullet weights like 120gr. And too, the 6.5x55 is mild.
As noted, any of these would be better than a 243Win. for big game hunting, even if just for deer.

Thanks everyone for the input and suggestions. I think I'm going to keep him with a 7mm-08 until he gets a little older. Thanks again!

James how can you say the 250 savage is better than a .243. It doesnt compare in velocity doesnt compare in energy and it certainly doesnt compare in trajectory. At 300 yds the 250 and 257 are dropping like a ton of lead with no energy left in them.
the .243 is by far the better choice, the .260 is also something to look at. A 25-06 really needs a 26" barrel so thats out of the question for a youth model. Go for a .243.

-------------------------------@300yds-------drop zeroed @ 100
Federal 100gr BT .243--------2380fps/1260ftlbs-----------11.4
Rem-100 gr-250sav.---------1936fps/832ftlbs------------15.3
Rem-117gr.-257.-------------1663fps/718ftlbs.-----------19.5

Now how does this equate to "terminally better"

I have shot about an equal amount of deer with the 250 Savage and the 243 and the 6MM Remington. The 100 grain 25 caliber bullet has a lower sectional density than the 243 caliber 100 grain bullet. I load the 250 Savage to about 2800 fps with the Nosler ballistic tip. It expands better than the 243 and just flat drops deer quicker and with very little meat damage. Ballistics are interesting and a good way to compare calibers on paper but in the field the 250 Savage has proven to me based on useing them both to be a better performer on deer size game. I think the reason it works better is that its not as fast. I could handload both to about equal velocity and ME but the 25 caliber bullet just does a better job for me. I even put the 250 on an equal footing with my 25-06 even though the 25-06 is faster and handles heavier bullets better than the 250. The 250 is one of those calibers like the 6.5x55 and 7x57 Mauser that perform in the field much better than their written stats say they should. Try one before you disagree.

I went the .243 route with my son and it worked out well. Now that he's grown though I think he'd be more happier with a larger caiber. What a friend of mine did seems to make the most sense and if I had it to do over again I'd do it the same way as my friend. What my friend did was buy his son a 7 mm Rem Mag with a muzzle break. In doing it this way the kid could have a rifle with the kick along the lines of a .243 but in a larger caliber, something he wouldn't grow out of.