John: There is no doubt in my mind that the second style joint check would work equally well with manual extractor guns; hammer or hammerless. But if this feature was indeed used on a manual extractor guns, then I would think that feature special ordered; in fact, I wonder if all guns with the second style joint check were special ordered given the fact that guns from the same production period may or may not have that feature. Obviously this device was unnecessary, but I personally believe this feature was discontinued because customers had problems with breakage and the resulting delimmna with barrel removal.