AR Five Seven (AR-57): 50-Shot 5.7x28mm AR-15 Carbine

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By David Crane
defrev at gmail dot com

August 11, 2008

An outfit called 57 Center is making an interesting patent-pending 5.7x28mm upper receiver for AR-15/M16 lower receivers called the AR Five Seven (AR-57) that utilizes 50-round FN P90/PS90 PDW magazines. The magazines are top-loaded and horizontal-mounted, just like on the P90/PS90. It would appear that that an emptied-out standard 30-round AR mag is utilized to catch the downward-ejected brass. While it could perhaps be argued that the 5.7x28mm cartridge has dubious terminal ballistics and it’s not necessarily a good idea to go below 5.56x45mm NATO (5.56mm NATO)/.223 Rem. in an AR rifle/carbine for tactical applications, the AR Five-Seven is an interesting product for anyone who likes the FN 5.7x28mmm PDW round and 50-shot mag capacity combined with an AR-15/M16/M4/M4A1-config weapon for recreational shooting/plinking. At the very least, the AR Five Seven is interesting as a novelty, and the 5.7mm cartridge is very pleasant to shoot.

The only problem DefenseReview has with the AR Five Seven carbine upper, just by looking at it, is that it utilizes a right-side-situated charging/cocking handle. Defense Review would prefer either a left-side-situated cocking/charging handle or an ambidextrous/switchable one. DefRev hasn’t yet tested the AR-57 carbine ourselves, nor do we yet have any testing data or field reports on the weapon’s accuracy, reliability, durability, or overall performance. We’ll try to get some, soon. The following comes from “TruWPN” in an thread started on 8/04/08:…

“The upper and lower color match perfect. I am really impressed with the quality. It still has the bolt open feature like the AR-15. It does utilize the buffer tube with the stock AR spring and a Heavy buffer that came with it. It ejects the spent cases through the mag well. I had a cheap 30 mag that was no good so I gutted it and cut the top off so it will work as a funnel for the spent cases. I purchased the Upper from who shipped and I received it over night. Great guy to deal with. Unfortunately I can’t find them for sale anywhere else and I got the only one Gordon had left. The Manufacturer’s web sight is I put 150 rounds down the pipe today after work with out a hitch. Really sweet accuracy at 50 yards open sights. And it was easy to engage multiple targets with no recoil throwing me off. I cant wait to put a optic on it. I am leaning towards a Aimpoint Micro T-1. Enjoy the pics…”

And the pics are pretty good. According to the same thread, is currently offering the AR Five-Seven carbine upper with one 5.7mm mag for $750, and “TrueWPN” got his (plus one P90/PS90 mag) for $780 out the door, including shipping.

So, if you like tactical ARs AND the 5.7x28mm cartridge, the AR-57 upper would appear to give you the best of all worlds. And, let’s not forget the neato factor.

Photo Credit: "TruWPN" from

Company Contact Info:

57 Center
8525 152nd Ave NE
Redmond, WA 98052
425-882-1161 Office
425-882-0487 Fax Email Info Email Sales Website

Additional Photos (Photo Credit: "TrueWPN" from

AR Five Seven (AR-57): 50-Shot 5.7x28mm AR-15 Carbine by

About David Crane

David Crane started publishing online in 2001. Since that time, governments, military organizations, Special Operators (i.e. professional trigger pullers), agencies, and civilian tactical shooters the world over have come to depend on Defense Review as the authoritative source of news and information on "the latest and greatest" in the field of military defense and tactical technology and hardware, including tactical firearms, ammunition, equipment, gear, and training.

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