Chiappa Resurrects the M6 Survival Gun w/ 10+ Caliber Options -The Firearm Blog
30-06 t0 308 adapter - The Firing Line Forums
X-Caliber Shotgun Gauge Adapter System
X-Caliber Shotgun Gauge Adapter System
Barrel Shroud/ Brake Adapter Protector Vented
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