Trying to see small holes at those distances will test even the best of glass....I can see rifle holes at 200 yards at dusk (w/Swarovski Glass) when everyone else is packing up for home. But 300-to-500 yards is beyond anything I've got.
Have also used 10X42 Swarovski binocs with 2X multipliers (which makes them 20X)....that's way beyond what they will do, even with a tripod.
Jim is right.....you need Hubble quality glass.
