bkdean
funksauer,
Your gun was proofed under the 1939 proof law, which mandated it be marked to reflect the name the cartridge was commonly called. The marking clearly indicates it is chambered for the Vierling (5.6x35R), rather than the Hornet (5.6x36R) cartridge. However, there has often been confusion concerning the proper cartridge for many of these rifles. The main difference between the latest Vierling and the Hornet, other than a small difference in ballistics, is the rim of the Hornet was thickened to prevent it's use in older 22WCF rifles. By the 1940s, the Hornet was pretty widely used but the Vierling was also still widely used, especially for hunting. Consequently, your idea to check the actual chambering has merit, in my considered opinion. It may have been made for either of the cartridges or subsequently modified to use the Hornet. When you check it be sure to carefully close the action because closing it with force on a Hornet cartridge case in a Vierling chamber can damage the gun. The fact that it is chambered for the more modern 70mm 20 ga. shells rather than 65mm lends some credence to the possibility of a Hornet chamber. When I handload for my own, verified, Vierling chambered BF, I use Hornet cases that have had the rims thinned from the rear and had the primer pockets deepened to match, with a primer pocket uniformer. I use common Hornet dies and shell holder with the modified cases and have satisfactory results. I use 45-grain .223" bullets and do not need to shorten them as you do with the 50-grain ones. If you have a Vierling chamber and do not have either the facilities or inclination to modify Hornet cases, you can use purchased 22WCF cases. Your rifle seems very nice, and you should be able to have many years of use and fun with it.
Mike
