On some replicas the pin notches in the hammer are too sharp, and will actually ''pluck'' spent caps, depositing them right down into the action, through the hammer's slot in the frame, causing the dreaded ''Colt Freeze''. Folks who don't know how to unsharpen the edges of the pin slot [useing a jeweler's file] routinely just plug it all up with JB Weld. A more elegant solution is a ''cap shield'', but that's more work than I want to do, when simply deburring the pin slot in the hammer will usually suffice.