Check for overall smoothness of the slide/frame...these were hand lapped from birth to finished product for a real smooth fit. Even if you have felt a little looseness it may still shoot well. Look at the bbl rifling, it should be pronounced with no ripples (indicating possible heavy loads being shot) Check the ball end of the bbl for contact with honed bushing all around or close to it. The accuracy mainly depends on 3 points of contact....bbl bushing fit, lockup in battery, and slidestop facing to bottom of bbl on the bbl lug (area that the slidestop contacts bbl behind where the recoil guides locks in). Other factors like head spacing of chamber, hood clearance in slide, overall tightness also have a great effect on accuracy. Your talking about a 148gr full wadcutter that gets released at about 750 to 800 fps depending on load. The weapon was guaranteed accuracy of 1.5 inches at 25yrds in a Ransom rest at the factory up to the time they were discontinued in the 90's
