Resolving power - terrestrial / target shooting

Recently my brother asked me what kind of scope he could get to resolve 0.30 inch bullet holes in paper targets at 500 yards. He mentioned some 20-60x 80mm ED spotter, but I have serious doubts about that.

Anybody have an opinion on this? Is it even possible?

Would a 100-120mm refractor at f8-f10 be capable, or maybe a 5" Mak?

Thanks for any ideas

Malcolm

A 4 to 5 inch aperture would resolve the holes, 100 to 120mm. In reality, the limiting factor in target shooting would be the mirage. Almost any sun at all would make most views at high power very unstable. If you look at a terrestrial target at about 500 yards with a 100 to 120mm scope at 100X you will see what I mean.
Dale

A bullet hole 0.25" diameter at 500m is larger than 10 arc-secs. That's a pretty easy target for an 80mm ED. However, you will need some magnification to see the bullet holes well. The holes can probably be detected at 30X, more power will make it easier. Much depends on the contrast of the hole in the target. As mentioned, the mirage effect can be quite destructive to the views if the sun is shining. Viewing over grass will help.

dan