Yep - that's where I wasn't sure about what constituted a 12-gauge for the purposes of the game, and if the omission of the 1920s from the commonality of the era was intentional (for game balance, maybe?) or if it was a mistake.
In my 7th Edition Keepers manual, Table XVII (pg 403) lists the 12-gauge shotgun (pump and semi-auto) as being common to the Modern era only. But prices for the weapon are noted for both the 1920s and the modern era. Is this a typo? Or was the 12-gauge (pump and semi-auto) meant to also be made available for the 1920s era?
The short of it is that I know next to nothing about the history of the 12-gauge (or any other firearm for that matter) and wasn't sure if it should be available to my 1920s campaign or not.
Thanks in advance!