The Burris is a good scope, I have a few of them, and love em.. But I dont think you scope is your problem,, unless its loose. Check all your mounting screws on your scope mounts, and check the screws holding your stock to the action/barrel. Did you shoot the tighter groups with different ammo? Lots of things could cause what your describing, but its doubtful it is the Leupold scope. Id take it to a gun shop and have all the screws checked for correct tightness,, dont overtighten.. and make sure you are always shooting the same ammo, brand, bullet weight,, etc. If all seems well, try it again in a vise with the gun held tightly and see if there is a difference.. Good luck.