AR-57

Not to be confused with Arkansas Highway 57.

The AR-57, also known as the AR Five Seven, is available as either an upper receiver for the AR-15/M16 rifle or a complete rifle, firing 5.7×28mm rounds from standard FN P90 magazines.^[3][4]

AR-57
The AR-57
Type	Semi-automatic rifle (civilian variant) Personal defense weapon Submachine gun
Place of origin	United States
Service history
In service	2019–present
Wars	Venezuelan crisis
Production history
Designed	2008–2016
Manufacturer	AR57 LLC
Unit cost	US$1,099
Produced	2008–present
Specifications
Mass	7.45 lb (3.4 kg) (AR-57 PDW)[1]
Length	30 in (762.0 mm) (AR-57 PDW)[1]
Barrel length	16 in (406.4 mm) (AR-57 PDW)[1]
Cartridge	FN 5.7×28mm[2]
Feed system	FN P90 detachable box magazines[2]
Sights	M1913 Picatinny rail[2]

It was designed by AR57 LLC.^[5]

Design

The AR-57 PDW upper is a new design on AR-15/M16 rifles, blending the AR-15/M16 lower with a lightweight, monolithic upper receiver system chambered in 5.7×28mm. This model is also sold as a complete rifle, supplied with two 50-round P90 magazines.^[1] The magazines mount horizontally on top of the front handguard, with brass ejecting through the magazine well. AR-15/M16-based STANAG magazines can be used to catch spent casings by taking out the feed lips, spring and follower.^[6] Sheet metal brass catchers can also be used on the AR-15/M16 lower.^[6]

Various scopes and other accessories can be mounted on the picatinny rail.^[7]

Unlike the standard AR-15 configuration which uses a gas-tube system, the AR-57 cycles via straight blowback^{[broken anchor]}.^[8] A fully automatic version exists and was marketed as a competitor to the P90 and other personal defense weapons.^[9]

Suppressed versions are also available.^[9]

User

• Venezuela: Venezuelan soldiers who defected to Juan Guaidó were photographed using an AR-57 during the crisis in Venezuela in 2019.^[10][11]