Steve:

A friend of mine asked me what that gun could be, so I called. The seller is a touch shy of exact details, but did say that the proof marks included ".475EX" which yields three possibilities - 475 3 1/4" NE, .475 No. 2, and .475 No. 2 Jeffery. The gun is set up for .470 cases, so the latter two are not possible. The .475 3 1/4" NE was never popular and was not widely chambered. The only makers I've ever seen multiple guns from in this caliber are Charles Lancaster, Cogswell & Harrison, and R. B. Rodda, with the vast majority coming from the latter two. I'm pretty sure this rifle was originally a .475 3 1/4" as it is marked ".475EX" and Cogswells and Roddas are unique in being common in this unusual caliber.

Given a DR with usable bores but buggered chambers, where possible, cleaning up with a reamer for the next size up case is the shortest and cheapest route from a useless rifle to one that can give good service again. You see these in various calibers from time to time, sometimes reproved, sometimes not. In recent years, I can recall an Evans .400/.360 Purdey that had been reamed to use the .375 Flanged Magnum case necked to the existing .366 bore, and a Rigby .450 3 1/4" NE that was simply rechambered to .500/.450 3 1/4" H & H. Both of those were re-proved.

BTW, there's another Rodda .475 3 1/4" boxlock for sale on Westley Richards' web site. Champlins has . C & H. .475 3 1/4" sidelock.
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