Thomas that is just a really cool gun. Never seen a 20 bore with barrels that long. Congrats on a neat find. :bowdown:

Belgian and likely after 1910 but pre-WWI
The barrels look to be fluid steel, but do not carry Smokeless Proof which was then optional and not atypical for tradename doubles intended for the U.S. market
It appears to have monobloc barrels so possibly by H. Pieper
The L bore is 16.4 mm = .646" and muzzle constriction 15.6 mm = .614" so choked 20g full at .032"
The chambers are almost surely 2 1/2"

Drew: The Barrels are Fine Damascus Steel and it has no. ser. no. It does require 2 1/2 shells with not much choke left in right barrel but left is fine. I took it to Pat Laib's gun shop in Spicer. It now will get a good cleaning. I have to dig thru my old shells and find some 2 1/2. Thanks Thomas

The smith will be able to tell Tom, but I'm betting (esp. if it's a Pieper) that is "Fine Damascus Finish"; a décalcomanie crolle pattern over (usually) decarbonized steel

https://photos.smugmug.com/Damascus/...o.%20107-L.png

Drew: Looking at the barrels on the top rib it does say Belgium Fine Damascus but even with a magnify glass it looks like steel with no Damascus showing. Thanks for all your help. Thomas

Fantastic! What a great find. Congrats.

boy you lucked out on that 20 with 40 inch barrels...if you find her sister send it to me....charlie

Short stuff ;)

https://photos.smugmug.com/Belgian/T...el%20Gun-M.jpg

would love to see and shoot danials squirl gun....i have an italian made over and under with 43 1/2 inch barells....its a 3 1/2 inch 12 ga....it was a 10 ga 3 1/2 inch and the fellow that had it build they slevved the 10 ga barrels with steel full length liners....it shoots good but is very heavy in the front....it weighs 13 1/2 lbs. at my age and haveing a stroke a while back the gun is to much for me now....but i still like those long barrels.....charlie