Ruger-57 20-Round 5.7x28mm Magazine

The Ruger-57 20-round magazine is the part to buy first for either the Ruger-57 pistol or the LC Carbine. Both guns run the identical box magazine, so a shooter who owns both feeds them from one inventory of spares. The Ruger-57 pistol ships with two factory mags and the LC Carbine ships with one, so spares are the do-first buy either way; four to six on hand is the realistic floor for a range day in 5.7x28mm, where ammo is expensive enough that nobody wants to stop and reload single rounds.

The body is black oxide alloy steel rather than polymer, which is the reason these run clean. Steel feed lips hold geometry better than polymer under repeated loading, and the witness holes on the spine let the shooter verify count without dropping the mag. This is the OEM spec Ruger validated the platform against, and it is the magazine to run when reliability matters more than saving a few dollars on aftermarket ProMag steel.

The full 20-round magazine is part number 90700 as a single and 90711 as a factory 2-pack. Residents of magazine-capacity-restricted states should buy the 10-round version (part 90712) instead; standard 20-round magazines cannot ship to California, Washington, New York, New Jersey, and other states that cap pistol magazine capacity. Confirm your state law before ordering the 20-rounder.