Here’s another lot at Gavin Gardiner’s April 18th Spring Fine Modern and Vintage Sporting Guns that caught my eye.

Lot 179: Henry Atkin self-opening 12-bore sidelock ejector, N0. 3296
Catalog info: 29-inch chopper lump barrels with 2 1/2-inch chambers, about 1/4 choke boring, the frame, locks and top lever with border engraving and retaining much original hardening colour, 14 3/4-inch well figured stock including 1/2-inch extension, 6lb. 9oz., nitro proof, leg-of-mutton case. Bores/walls: Lt: 735/25 & Rt: 738/22. Estimate: £4,000-6,000
Pros: Appears to be an Atkin Spring Opener (built on a Beesley action), lots of original color on the action, unusual engraving pattern.
Cons: Big bores, marginal walls in right barrel, stock extended and probably refinished, barrels probably reblacked.
Henry Atkin opened his own gunmaking business in 1877. In 1907 he introduced his self-opening double. From the Atking, Grant & Lang website: “The gun is essentially the Beesley/Purdey 1880 patent spring-cocking mechanism, with alterations to the ejector system and cocking pads to make the gun easier to close. Many aficionados believe this the very best of the self-opening side-locks; giving the advantages of the self-opener without the stiffness associated with the Beesley design upon closing.”