mine also on the 450's gives different readings -1 or+1yd or 2 I'm not nocking bushnell either for $150.00 they serve themselves to be ok,but I have never been able to range anything with them over 220yds. I would never take them know where on a hunting trip where I could shoot out to 300to400yds.with a rifle. but for bow and ml they work just fine,when life gives me the opportunity I will upgrade to a better pair.........Ted