If you're trying to see bullet holes in a paper target, I'd recommend using Shoot-N-C type targets that are much easier to see than just a hole in paper. They are more expensive, but I can easily see .223 rem hits at 300 yards using even a cruddy spotting scope.
I had a Vortex Diamondback spotting scope (20x60x60, retail $400) that was far better than the cheap scopes they rented at the range that worked just fine at 300 yards, as long as I was using a Shoot-N-C type target.
I sold it recently to fund something else, plus my girlfriend told me that if I'm nice and take her to Hawaii in 2020, she'll get me a Viper for my b-day this year. So I'm trying this "being nice" thing.