I want to put the VX!12-7 x 33 scope on my AR (.223/556) for 100-150 yard shooting. But the guy behind the counter at Bass Pro Shops says that Leupold will not honor their warranty (if anything goes wrong with it) on it because it's mounted on an AR rifle. (Too much vibration on the 223). Anybody heard of such a thing? I'll be using it for hunting.