I agree with HighWall's observations and, a pigeon gun will almost never have 2 1/2" chambers. This gun's too light, and the barrels are on the too-short side. Pigeon guns are built to handle 3 3/4 - 1 1/4 loads, generally, and being British, proofed for same. Few pigeon guns would have a choke as open as .023".
Pigeons are going away, much/most of the time, and any difference in choking of the two barrels would favor the more open one on the first shot. Incoming birds are the opposite. One would use the more choked barrel first, then the more open barrel second. I do this without exception on incoming doves and ducks.
All these things taken into consideration together tells me this was never built to be a trap pigeon gun.
SRH
