I personally feel the 3-10 range is suited for big game hunting out to 500 yards, which is as far as I would shoot at an animal. Though most of my shots are 300 or under, I have taken some over the years that were past 300. This year in fact I took my mulie buck LRF @ 407 yards at 10x with a solid hold I had no problems putting the bullet through the lungs and dropping the buck. I have a few higher mag scopes but like mentioned the higher the power the more noticable the shake and also the smaller the field of view. I don't like hunting for the target in the scope so therefor I tend to run lower and power up when needed while on target.

Shooting paper the higher mag is nice no doubt about that.

As mentioned its personal preference on what is best to you.Like trailer I'd talk to your uncle, plus ask to tryout his scope/rigs to see what you like or dislike before you purchase.

Good Luck