What would be the top reason(s) for a single action revolver to miss the half cock position? When the hammer is pulled back to half cock so loading may be done, it clicks but the hammer will not stay back. Thus causing other problems as well.
It's a black powder colt army.
Also the bolt is staying engaged during the full cycle of the hammer being drawn back. It only drops for a split second when the hammer reaches the point where half cock "should" be, the bolt pops back up (causing some go awful bolt drag lines
)