Even with one of the clearer and best scopes like the Swarovski scopes adjusting to higher resolution results in lesser clarity since it magnifies the mirage effects.

Yes having a scope with excellent clarity, with a larger objective lens to capture more light and transmit the image to you is fairly essential.
But to have it capable of being adjusted to 30X or 60x magnification will only blow up the mirage for you.

Setting the scope to 20X to 24X magnification is most ideal to see the image with the least impact of exploding the mirage and loosing clarity.

The other problem is when the sunlight is being directed into the back of the targget or straight into your scope since you then cannot make out the bullet holes.

Ideally a north facing range precludes the direction of the sunlight right at you.

Using a red filter (available from camera stores for use on cameras) will filter out UV light and reduce the scatter of light allowing you to see bullet holes easier. 
Makes them show up as black holes instead of bright light being focused directly back at your eye.

Some scopes may be able to have a red filter screwed to the front lens.

Or you can buy a smaller diameter filter and just hold it over the rear lens when you look through the scope.
 
Been there going down the rabbit hole trying to find a better scope when the most effective investment was obtaining a relative inexpensive red filter.
Red filters improve the contrast of the image being transmitted.

Red filter transmits only red light and absorbs all other colors. 
In this ideal case, a picture containing red, green, and blue would appear red and black when viewed through a red filter. 
A red filter blocks green light and blue light: Only red light can get through to your eyes.

Never tried the filters, agree the scopes we typically use target shooting about 24 X fixed is the optional ocular lens. I have heard people say 32x resolves well on on Unertl  100 mm team scopes, mines missing the 32 can’t say sure. Rarely take the 24 off, have used the 15x at times, morning ground fog mostly. Finding the target not spotting holes.

The high power variable is popular with bird watchers. I do some late fall watching  migrating hawks Cape Charles Va. Hawks bunch up poor visibility days waiting for clear before making the 20 mile Bay crossing. The dedicated birders use high power binoculars and spotters. Thing I notice is they don’t look at a bird very long. Soon as it’s identified write it down and look for another. Never study the bird in detail the way we do with a target.

Many years ago pre modern electronics on a CG Medium Endurance Cutter we used 3 glasses. 7x50 Binoculars scanning the horizon, lookouts on a 4 hour watch. 10x deck telescope, hand held, used by the OOD to confirm the object lookouts reported. Quick look only no scanning. 3rd glass racked and used by the quartermasters plotting positions 16 x telescope, again hand held, to confirm markings on Fixed aids. Bouys mostly, they had been pre identified off the chart. Quartermaster read the number to double check position. Very brief look at shorter distances. 

Point is every use has a best glass, good for one not necessarily good for another.

Boats

My clubs mostly offhand on steel. I do shoot the ASSRA 200 target  black side iron red side scope.  Red much easier to spot   However painted steel very easy to spot 22 at 200 yards.    Paint chips off making a larger spot.  Practice it’s good method