Two pipe, several years ago I had the pleasure of owning a Diamondback 6". I also had a problem with it key holing from one chamber, it also shaved lead. Seems that that chamber was out of time. Colt repaired it. If you have all six key holing that would indicate a possible problem with the hand or the barrel could be damaged at the crown, Has the barrel been cut off? If yes the crown is messed up.<p>Sure wish I had that little beauty back.<p>Bullwnkl.