https://ajcgunshop.com/gun-parts-magazines-wgun-112029901-mag-sxr-300-wsm.aspx

Winchester 3 Round Blue Magazine For SXR 300 Winchester Short Magnum These magazines are for the .270, 300, and 30-06 Winchester SXR model rifles. They each hold 3 rounds, except for the 30-06, it holds 4 rounds.