It's a rare bird, Geno. Butler gives it a couple pages in his "The American Shotgun", not because it was American but it seems he wanted to discuss all action types.

The US patent is 954,546 issued to C.A.T. Sjogren on April 12, 1910.

Inertia operated gun. Made in Sweden, but Butler specualtes that many may actually have been made in Denmark. My guess is that production was confined to the 19-teens.

Ingenious and way ahead of it's time. I would very much enjoy the opportunity to examine one.

"The price of good shotgunnery is constant practice" - Fred Kimble