This is an excellent example of a very unusual and very rare Model 12 riot shotgun in 16GA. The right side of the receiver is marked with the large "U.S. and Ordnance bomb" proof and the left side of the buttstock has the boxed "WB" cartouche and crossed cannon ordnance cartouche. The barrel, magazine tube and receiver have the Winchester commercial blue finish and the forearm and stock have the commercial Winchester varnish. The stock has the black, hard rubber buttplate with the impressed Winchester logo in the center. The left side of the barrel is roll-stamped with the two line New Haven address and proof steel markings followed by the two line Winchester trade mark followed by "2 3/4 CHAM" over "-MODEL12-16 GA/CYL." in two lines. The serial number "976135" is located on the underside of the receiver and the magazine tube. A smaller "Ordnance Bomb" proof is stamped on the top of the barrel immediately in front of the WRA proof. It is complete with an original box of Winchester "Western Xpert" 16 GA shotgun ammo that is "US PROPERTY" marked on top of the box over "No1 Buck Shot". All U.S. contract Winchester Model 12 riot shotguns in 12 GA were produced in small numbers than the Model 12 trench guns, both of which are very difficult to find in this condition. With this one being in 16 GA, it has to be extremely rare and is worthy of additional Winchester factory research.