The AR-57, also known as the AR Five-seven, is an upper receiver for the AR-15/M16 rifle lower receiver, firing 5.7×28mm rounds from standard FN P90 magazines. It was designed by AR57 LLC and is currently produced by AR57 of Kent, Washington, USA. The AR-57 PDW Upper is a new design on an AR-15/M16 platform, blending the AR-15/M16 lower with a lightweight, monolithic upper receiver system chambered in FN 5.7×28mm. This model is also sold as a complete rifle, supplied with two 50-round P90 magazines. The magazines mount horizontally on top of the front handguard, with brass ejecting through the magazine well. Hollow AR-15 magazines can be used to catch spent casings.
Unlike the standard AR-15 configuration which uses a gas-tube system, the AR-57 cycles via straight blowback. A full auto version exists marketed as a competitor to the P90 and other personal defense weapons.Now, here it is in Lego form.
About this creation
Here is the AR-57, made out of 1981 bricks including the bullets. The model is built on my Ares LMG but the upper receiver change significantly.
Here is the upper receiver detached from the lower receiver.
The gun uses the P90 style magazine to chamber the 5.7×28mm round.Same applies here in Lego.
The charging handle works like how it should.These pictures shot it to the rear and to the front.
Just like the real one, brass ejects through the magwell.Hollow AR-15 magazines can still be attached inside the magwell to collect spent casings. Unfortunately, the lego magazine is completely solid and does not function at all.