Abstract: A magazine loader having a base member and support members, the base member being configured to sit upon the magazine fixed to a rifle, the base member having a first end wall, a second end wall, and a pair of sidewalls defining a rectangular shape, wherein the first end wall has an opening that allows the base member to sit upon the magazine fixed to a rifle, wherein an entirety of the second end wall and an entirety of each of the sidewalls are coplanar, wherein the support members have a first support member and a second support member each extending from a top surface of the base member, wherein the first support member has a plurality of support lips that forms a channel that is capable of accepting a retainer strip of cartridges, and wherein the second support member receives a bullet end of a cartridge, and related methods.