I took delivery of a NIB flattop bisley .44 special...it has a problem, and rather than spend the funds to send it back to Ruger, it seems an easy enough repair. What the problem is is it won't rotate the cylinder when cocking the hammer back when the barrel is pointed upwards. It will cock and rotate the cylinder in the horizontal plain, and with the barrel pointed downwards, but not up. Upon examination with the cylinder out, I found that the cocking arm/ratchet (for lack of knowing precisely WHAT that part is called) seems to need a spring behind it to push it outwards to engage the notches in the cylinder. Could this spring be missing? If so, are they much trouble to install? I am very adept at smithing on S&W revolvers, but haven't been inside Ruger Blackhawks before, other than to replace the hammer spring with a Wolff. Thank you for your time and replies.