This is the Loading gate (spring cover), also called spring cover Winchester 94 POST 64 in.357 mag. It fits .357 mag angle eject above serial number 6,000,000. Note: The Loading gate (spring cover) for .30-.30 is part number (c131) . 450 marlin, 44-40, 44rem,45 colt is part number (c136). The screw that attaches the loading to the receiver is part number c104-a.