Size Doesn't Matter (Much)
The latest issue of Petersen's Rifle Shooter has an interesting article on barrel length and velocity in rifles. They look at several common calibers (including magnums) and find that the velocity loss is 15-20 fps per inch when shortening the barrel. This is much less than the common rules of thumb which estimate velocity loss at 25-50 fps per inch.
These results are consistent with Rifle Magazine's test of the Ruger M77 Compact in the March issue. This model has a 16.5" barrel yet produced velocities only 90-110 fps slower than 24" barrels.
All of which is great news if you are looking for a woods and brush rifle. The Ruger Compact and Remington Model 7 still deliver modern velocities in these short packages.
I hunted last year with a Ruger Compact. To me, it is the perfect rifle for deer and black bear. Overall length is only 35.5" and weight (with scope) is just a few ounces over six pounds. It is actually shorter and lighter than most leveractions.
In a daypack a pound or two doesn't matter much for eastern hunting. But when it is carried in the hands like a rifle, a little less weight matters as the day goes on. The length, though, is the big benefit. Compared to my 30-06, there is 6" less barrel to get snagged or caught in brush and grape vines.
The rifle is more accurate than i am. With Remington factory ammo it held to 1" at 100 yards off sandbags. I'm sure it could do better, but i am not an accomplished bench rest shooter.
Finally, in, 260 Remington, or 7mm-08, either model are near perfect deer rifles for kids. Recoil is manageable and the shorter lighter package is easier to handle for short or small shooters.