I had one on my 25-06 tactical with no problems, I have it on one of my .45 Knight now and have had no problems. I do think the Diamond Back is a much better scope, I have 6 or 7 of them along with a few Vipers, NO PROBLEMS at all. IMO the Viper is just a little to long for me. Over all VORTEX is one hell of a scope, there Binocs, and Spoting Scopes are second to none.