12ga. With 7.62x39 insert - Louisiana Sportsman Classifieds, LA
Short Lane, Shotgun Adapter, 8" Rifled, 12 Gauge to 22 LR Pathfinder Series, Fits 12 Gauge Break Open Shotguns - Aztech Armory Canada
Amazon.com : StrongTools BoreSighter for 223/9MM/7.62X39MM/30-30/30-06/.25/270/243/308/7MM/ 45ACP Colt Caliber Rifle Scope Handgun Brass Red Dot Boresight Kit for Hunting with AG3 Batteries (Special, Bullet Type) : Sports & Outdoors
Adjustable Bore Sight .223 7.62x39 7.62x54 30-06 308 12GA 20GA 30-30 Cartridge Red Laser Boresighter - Price history & Review | AliExpress Seller - Hunting expert Store | Alitools.io
Could the use of 'adapters' which fit into the chamber and swapping of the bolt, extractor and other parts allow firearms to use different calibers as long as the new cartridge is
X-CALIBER Survival-Rifle Gauge Adapter System - Soldier Systems Daily
Chiappa M6 X-Caliber Over/Under 12 Gauge/.22 LR 18.5" Barrel 3" Chamber Single Shot
X-CALIBER Survival-Rifle Gauge Adapter System - Soldier Systems Daily