Cat, about 12 years ago I bought two Webra SilverLines, a .40 and a .61. Wile breaking in the .61, (very carefully) it developed a clicking internally after about an hour of run time. It turned out that the upper rod bushing was just a hair tight and the wrist pin was rotating in the piston's wrist pin bores and wore them oblong. It's amazing what can happen. Paul at Paul's Model Supply in Fargo, ND fixed me up with the necessary parts and all was fine.