Kerr Army revolver 1858

My father told me to post some antique british firearms so i choosed one of the best, the Kerr revolver.
Designed by the English gunsmith John Kerr in 1858, this revolver was produced by the London Armoury Company. Some versions had a small sear below the external hammer; After cocking it could be locked. The pin from behind the hammer is the removable cylinder pin. In 1859, Kerr built a double-action revolver at the request of the British Army. Although this fire-arm wasnt chosen as a military revolver, was very popular, particularly in the British colonies. This revolver was also used by the Portuguese Army (.440″ calibre version).
TECHNICAL SPECIFICATIONS:
-Calibre: .380 or .440
-Catridge capacity: five-shot
-Operation: single-action M1858 or double-action M1859
-Firing system: percussion
-Breach-loading: N/A
-Length: 280 mm (11″)
-Barrel length: 140 mm (5.5″)
-Weight: 1220 g (43 oz.)
-Grip: nut
-Sight: fixed
-Safety: half-cock hammer