Physical size has nothing to do with the size caliber a hunter uses...I'm
6' 5", 250....Have used a .243 since 1980, killed at least 150 deer with, it works just fine....My brothers use the 7mm-08 and .270, they also work...
We see no difference in how far a deer travels after the shot with either a center lung shot or high shoulder shot....Each year we kill 40-50 deer on our 3 farms, spread that out over 25 years or so, it should give you a pretty good basis for comparison....

One thing my brothers have noticed is that I make better shot placements than they do, thus my deer either drop on the spot or within 50 yards.....

There are 4 advantages that I have noticed that come with using a rifle that is a light kicker....1) I use it year round, crows, coyotes, groundhogs, whatever, it's what I use...2) I never lose sight of the deer after the shot, I keep the scope on them, so I see the result 3) I can shoot from either shoulder, if a deer appears on my off shoulder, I flip the rifle over and take the shot, no need to stand up, turn around and get on the deer, which can easily spook them before the shot...4) Since I enjoy shooting, I practice more, making me a better shot, my brothers actually get me to sight in their rifles, because they don't enjoy shooting as much as I do....

On the "age" thing...I'm 52, guess I'm still too young to move up to a "big boys" gun...