The locks on a sidelock shotgun are a lot like the mechanics on a nice watch: intricate, precise, beautifully made, and rarely seen. That’s too bad, because they’re something to be appreciated.
So to that end, here’s a quick look at two of the most famous styles of locks ever made: the Beesley and the Holland & Holland.
The first two pics are of Beesley-patent locks off of a Purdey pigeon gun. Check out how big the main spring is. This is because the spring performs two duties: it fires the lock and cocks it. These locks are cocked, btw.


This next pair of locks is off of a Hussey shotgun. I think they’re pretty straightforward H&H 1894-patent style.

To read more about these locks and the see a detailed discussion of their parts and evolution, check out this chapter from Steven Dodds Hughes book Double Guns and Custom Gunsmithing.
Pic of the Hussey locks are courtesy of VintageShotgun.com.