A lot of original style Mule ears were made with no half postion..
Part of the problem with the high pinned long trigger bar.. is depending on how the are made.. some have enough weight to cause a misfire if the butt of the stock is bumped or set down roughly. The inertia can cause enough rearward trigger motion. Some have gotten around it by adding a simple spring to help keep the long bar trigger forward..I'm not sure who made these locks, but am thinking they are not antiques? someone with a lot of skill and ability have made some nice examples of the Mule ear lock.
The Mule ear lock is true American design. none were made in other countries, until examples were carried over from the States. Primarily an eastern made gun/lock design. Jenk's had a patent for a mule ear lock issued in 1837 and his example that was used in the Civil war was a 1839 improvement of his design. His gun was
only the third model of its type adopted by the US military.. the only one that was a side hammer/Muley and the only one who's main retaining element for the lock was the percussion cone..
this is a drawing I made from the measurements my bud and I got from working on a fellows Navy Arms "Poor boy" at the bottom of the page you can see the two piece camming trigger.sear trip. easily converts rearward motion into a rearward horizontal stroke. Years back, Laurie Fenton, from Woy Woy NSW
had an article printed that showed his method for making his version of the Mule ear lock. His design also utilized the camming sear trip and trigger. by adding a bellcrank mod.. the sear can be tripped by a normal trigger and if the lock is designed correctly it can even use a version of the normal set trigger to fire the firearm. the bell crank turns the <normal> vertical trigger swing into an inward/sideways motion that can trip a sear arm..
A fellow named Rick McGuckin is actually researching and writing a book detailing the History of the Mule Ear Lock.. Medberry, Billinghurst, Cooke and Greene are some of the names of the past builders who made Muleys in the Good Old Days.
Respect Always
Metalshaper/Jonathan