As a personal thought, I believe that more than a few repeating rifles were purposely converted to single shot operation specifically for use/sale in the western reservations. Do a simple web search for: 'Great Basin National Park 1873 Rifle'. There are numerous links well worth wading through. This 'lost then found' again lever gun had so been converted to single shot operation. Inspection and even x-ray's revealed that parts needed for the rifle to function as a magazine repeater had been removed. Magazine spring and follower, cartridge carrier and lifter arm are missing. That left only the trigger, hammer, bolt, bolt toggles, lever link pin and lever in place. In the case of this particular 1873, the butt stock cleaning rod chamber contained an un-fired cartridge stored inside. Such a single shot conversion is still possible. I've tried it just for grins with my 1860, 1866 and 1873 carbines and it does work assuming you don't fumble a cartridge and it drops out the wide open carrier cut and falls to the ground.