It's not about available magnification, it's about optic quality. The cheap spotters fall off the cliff optically as soon as you wind them up.
My old Kowa TSN-1 with a 25x fixed lens would see 30 cal bullet holes, with the light in the right position, on the 300yd fullbore targets. At 100yds I can watch very small insects crawl across my target.
I bought a Sightron SII 4-16 just for 22rf 50yd - 100yds shooting and I couldn't see bullet holes clearly at 100yds on 16x, and only just at 50yds! Most disappointing as I have a Sightron SIII which is great. The SII got returned and replaced with a superb Weaver 4-16 x 44 EBX. Of course the Vista Outdoors wackers shut Weaver down or I would have bought a couple more of them.
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