12GA to 10MM Shotgun Adapter - Chamber Reducer - Stainless - Free Case & Ship !! | eBay
577/450 Martini Henry to 45 COLT Rifle Adapter - Chamber Reducer - Stainless
Reusable Personal Protection Device Powerhead – Spear Gods
SightMark Accudot .243/.308, 7.62x54, Red Laser Boresight | Customer Rated Free Shipping over $49!
Cartridge Conversion Sleeve Insert, 7.62 x 54R to 7.62 x 25 Tokarev | Gun
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
Firefield 7.62x39 In-Chamber Red Laser Brass Boresight FF39013