The invention of the percussion lock doubtless stimulated many craftsmen to improve on the early pattern. The function of this side hammer or "Mule ear" lock was satisfactory but it never was popular with gunners and few of them were made. Some of them were made by men who seem to have been experimenting rather than producing locks in quantity. A side hammer lock in Henry J. Kaufman's collection has the mainspring on the outside of the lock plate.
Although this lock is the only one known to the writer made by Drepperd of Lancaster, Pennsylvania, it is not surprising that he made one. He was a fine craftsman and it is reasonable that he would try his hand on this strange style. It also possible that he made it for a customer who specifically asked for such a lock. It is obviously the shape of a standard percussion lock and is beautifully engraved in the style and workmanship of a fine lock maker.
