MS, I recently bought a Fujinon 80mm spotting scope with a 20x60 zoom and I can see .30 and .22 cal holes at 300yrds with no problem. I don't shoot black targets (I make my own targets on the computer and copy them on light colored paper) and so far heat distortion has not been a problem. The two down sides so far are the price($550 at eagleoptics.com) and the size. The up sides are good quality optics for a lot less than the top brands and not having to walk or drive to the target. I Don't know if the large objective lens makes any difference but I also wanted to be able to watch the deer in our pasture in low light situations so I spent the extra $$. If you are looking at the lower priced scopes you should try one out (if possible) before buying. Good luck.