In my opinion the magnification you listed is too low.
If you really are and I have no doubt that you are shooting some type of rifle at that distance.
I think the highest magnification you could get would be needed I use 60X to look at 100 yard targets and sometimes have trouble.
Interesting thoughts as I have a 25X Bushnell spotting scope, made in the 60's that looked old in 1974 as it was mounted on a post at the Barnet Range in Burnaby, B.C.
I got it from a relative, who obtained it when that range closed down in the late 1980's, I think. At that range, when shooting competition in those early 70's we only shot to 100yards and it was
easy to not only spot holes but also multiples, ie:hole enlargement. Of course that became quite impossible, somtimes after 3 in the same hole.
I can easily see .224" holes with that spotting scope at 220yards - indeed, did so yesterday at the local club.
Quality of lenses is very much more important than magnification power.
For spotting to 1,000yards, fleener, I'd think something on the 30X, 40X to perhaps even 60X would do, but would need very large, excellent glass lenses (for brightness & clarity) to see well at
long range. BEST quality glass at 30X to 40X will show holes that 60X in a lower quality scope might not. I would look towards Swarovski glass.
I agree that 10 to 20X is too low, even for larger bullet holes like .45's and .50's.