Personally, I would not having him shooting equivalent of 30.06. He may handle it for a couple shots, but I remember when I got my first 30.06, as a small and young boy, I got so flinchy on the range, after several shots, I couldn’t even hit the paper. I ended up getting a muzzle brake to help...
.270 or 30.06, will always be great for those animals, and just about anything. However, ballistically speaking, there are new calibers that take it to the next level. .270 WSM, is one of those improved calibers.
From those in the know, selling commercially or owning them, it is a great caliber out to 5-600 yds. I have heard it called facetiously, 6.5 Needmore. Because of that, I purchased a 6.5 PRC. USE IT ON DEER, antelope, sheep, even elk at average ranges. It will shoot flat and be fine.
With only 6 pts, chances are, you may never draw a sheep tag again, due to point creep. I would never turn that tag in, unless you had maximum or near maximum points.
This may be much more simplified than it really is, but I wonder if there is a type of medicinal treatment that could be added to feed, where large herds are fed during the winter, to slow CWD?