To the gang,
Muley's are an interesting gun lock and makes for a fine and fast rifle, when it comes to shooting. Historically they are of the very late percussion period and most do not have a half-cock position. Seems these locks were used mostly in target shooting and not so much for hunting.. at least that is what I've found in my research.
The Link to Laurie Fenton's web site,, is a good one. I borrowed some from his designs, when I built my "Miss Muley". Laurie and I exchanged ideas and he helped me overcome some of the geometry problems I was having in my own lock design. The results were this...
My lock design incorporates a half cock position and I also added a fly to the tumbler/hammer mechanism. the mainspring is a coil spring and the two stage camming trigger is a somewhat copy of Lauri's design.. < I just condensed it into a smaller package > The gun is a take down and I have tw barrels fit to the action. the .36 cal rifle barrel < shown > and a 28 gauge shotgun barrel, that is octagon and was made from a reamed out .50, that I aquired from a gunshop.. I need to find a decent Big bore in 15/16ths acf,, to complete the set.
If your geometry is good, it's easy top add a half cock position. If your using a Storey style < I have seen some home made versions > you could add a "safety lock" that engages the hammer to stop it fall,, or use a lever to position a stop under tha hammer to prevent it fall.. at the very least, a turned brass "cover" could be made to set over the nipple and be held fast by the hammer is another option, < my buddy uses this type on his UH > by having a thong or small chain attached to the trigger guard,, when the hammer is cocked it falls away..
Better go
Respect Always
Metalshaper