Well, I managed to pick up something a little bigger. This is Britains 18" Howitzer. It is a typical WW1 heavy artillery piece, with a heavy carriage used for long term emplacement for siege duty.
The gun has a working elevation mechanism and a hinged breech where a metal shell with lead projectiles are loaded.
In the photos you can see the ammo for the gun. The three different spring lengths allow for three ranges at full elevation. I have not tried a full length shot yet, but the lead rounds really fly out of the muzzle.
A pic with a 1/32 scale British Royal Artillery man gives an idea of the size. The breech mechanism is missing in One picture as I removed it to clean and repair. I replaced the "field expedient" nail in the firing mechanism with a machined pin.
