ProMag RUGA42 5.7x28mm 20rd Magazine for Ruger-57 Blued Steel

The ProMag RUGA42 is a 20-round detachable pistol magazine designed to fit and function in the Ruger-57 chambered in 5.7x28mm. It gives Ruger-57 owners a high-quality spare or backup for range days, training sessions, or everyday carry.

The magazine body is constructed from heat-treated steel finished in black oxide (blued) for corrosion resistance and long service life. Inside, an injection-molded polymer follower and a heat-treated spring keep rounds seated properly and deliver smooth, reliable feeding round after round.