I have a Star PD 45 pistol. When I fire it the barrel is failing to completely downlink and unlock. However, when I cycle it by hand it downlinks and unlocks perfectly. The link, pin and bottom lugs are in fine shape. I can find no evidence of battering on either the lugs or the frame. Frankly, I'm stumped. If anyone has had this problem before or has some ideas your help will be greatly apreciated.