All my records indicate that stevens did not make a model 337 shotgun.If your stevens shotgun is marked U337 under the receiver,this would be a serial number,not a model number.
If the "U337" is stamped on the lower tang it is the serial and not the model number. There was a really large range of serials like this used on Favorites and Visible loaders.
1 x 337, 337 x 1 = 337
No published data known.
1 and 337 (337 is a prime number).
1, 337.
337 = CCCXXXVII
337, 674, 1011, ...
-337
337 x 1
Ten percent of 337 is 33.7
0.337 = 337/1000
337 AC is the fourth century.