Gun Parts Co. used to sell a sporter conversion kit for small ring Mausers- - - -a short-chambered .308 barrel with the small ring thread, and a spring, follower, and spacer to shorten the magazine well to the proper length to feed the 7.62 X 39 cartridge reliably. I built one for my granddaughter's first deer rifle, with a 3X9X40 scope, in a synthetic stock. She took her first deer with it at age 13. I loaded it with Hornady 130 grain .308 spire points at about 2200 FPS.
