I have two of the extensions for my Contenders from the manufacturer that isnt allowed to be named on this board! Several of my shooting buddies have the same extensions, except for Encores. Among all of our Contenders and Encores, there must be literally 10s of thousands of rounds fired with these extension in place and not a problem to my knowledge. At least not a problem with mine. They have never worked loose and they fit the hammer like a gloveNo slop, No movement. We all found that when hunting with them (Contenders and Encores) in the cold months and while wearing gloves, it was nearly impossible (and maybe dangerous) to attempt to cock the hammer when the Contender or Encore wears a scope. Allowing the hammer to be uncocked is even a trickier task while wearing gloves and no extension in place. As a matter of fact, I just receive two more extensions for Encores in the mail the other day. One I will keep for myself and the other one my brother-in-law bought from me. Good-luck
BCB