If you're shooting off a rest and the weapon is off 3" from the previously installed sights, then it make sense that the new ones were installed improperly. That is one reason to NOT use a brass punch, unless you know what you're doing and can correct a problem later. Too easy to start frigging with a good weapon and then have problems. Get good sights, have them installed properly and forget about. If you've spent close to $1,000 on the weapon, magazines, holster, etc. etc. etc. why are you being cheap with the one thing which insures accuracy?