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
![Amazon.com : MOSANDON 7MM Red Dot Laser Bore Sight,Cal. 7MM Boresighter,Lase Bore Sight 7MM Remington Mag Rifle Cartridge Laser Boresighter with 2 Sets of Batteries … : Sports & Outdoors Amazon.com : MOSANDON 7MM Red Dot Laser Bore Sight,Cal. 7MM Boresighter,Lase Bore Sight 7MM Remington Mag Rifle Cartridge Laser Boresighter with 2 Sets of Batteries … : Sports & Outdoors](https://m.media-amazon.com/images/I/51JBsfYqsIL._AC_UF1000,1000_QL80_.jpg)
Amazon.com : MOSANDON 7MM Red Dot Laser Bore Sight,Cal. 7MM Boresighter,Lase Bore Sight 7MM Remington Mag Rifle Cartridge Laser Boresighter with 2 Sets of Batteries … : Sports & Outdoors
![Auxiliary cartridges By any other name, still twice the fun - TheGunMag - The Official Gun Magazine of the Second Amendment FoundationTheGunMag – The Official Gun Magazine of the Second Amendment Foundation Auxiliary cartridges By any other name, still twice the fun - TheGunMag - The Official Gun Magazine of the Second Amendment FoundationTheGunMag – The Official Gun Magazine of the Second Amendment Foundation](http://www.thegunmag.com/wp-content/uploads/2019/03/HL-30-30-300x215.jpg)