The 7 was one of a series of semi-auto, recoil operated rifles offered by Winchester. I believe there were 3 centerfire models in 4 calibers, and 2 models in .22 Long Rifle.
The Model 1905 was chambered in .32 & .35 Winchester Self Loading. They were pretty much worthless cartridges. But, as an interesting trivia note, the .32 WSL formed the basis for the US .30 M 1 Carbine round of World War II fame.
The 1907 was chambered for .351, and the Model 1910 was chambered in .401 WSL.
The 07 was, by far, the most popular. It was decently powerful, relatively light, and very handy. Some saw service with French forces (primarily their Air Force, IIRC) in the early days of WW I, while many thousands were sold to police forces and hunters here in the US.
Some police still carry the .351, even though the round is functionally obsolete and ammo is getting a lot harder to get.
They're nice little rifles, but if you reload you have to pretty much match factory ballistics, as there is no way to adjust the recoil system to account for differences in ammo power.
