DSA ZM4 A3 AR15 Upper Receiver

DS Arms are now selling half-assembled AR-15 receivers. Half assembled means no bolt, bolt carrier or charging handle.

  • Forged 7075T6 A3 Flattop Upper Receiver
  • Forged Front Sight Base with Bayonet Lug
  • A2 Flash Hider
  • 16 Inch 5.56mm NATO Nitride Treated Chrome Moly 1:9 Twist ZM-4 Barrel
  • M4 Style Handguards
  • Aluminum Delta Ring
  • M4 Style Feed Ramps

The introductory price is $275.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Erwos

    Actually, that could be super-handy for those of us who want to build an AR-15 in .22LR on the cheap.

  • anon

    For a _dedicated_ 22lr AR, I’d want a dedicated barrel to avoid using a chamber adapter.

    Also, for the majority of 22 ammo, you’d probably want a more conventional 1:16″ twist.

    That said; the 1:9″ twist would be good if you wanted to build a suppressed rifle to use Aguilas 60Gr sub-sonic rounds. Very Hush Hush.

  • Wow, that is a great deal – thanks for the heads-up!

  • Tony Chow

    It’s a mediocre basis to build an .22LR upper with decent accuracy. You are handicapped by that .223 chamber and twist rate.

  • Matt Groom

    Nitrocarborized barrels? As in Tennifer/ Melonite? I find this VERY intriguing (I tried to convice someone to do this on his guns once!) I am under the impression that Nitriding is the same as Ferritic Nitrocarburizing, but that Carbonitriding is different in as much as it is performed at much higher temperatures. I get confused, so if somebody knows more about surface treatments than I do, please correct me. It should be more durable than hard chrome and more corrosion resistant than Stainless Steel! I might just have to buy one and see how it holds up!

    I just don’t understand the fascination with .22 ARs. Yeah, you have the same (usually heavy) trigger that you do with your go-to gun, but you also have a .22 conversion kit, or upper, or devoted rifle that costs as much or more than dozens of other arguably better .22 rifles on the market. For the price of a devoted AR .22 upper, I’d rather have a decent bolt action .22 and a suppressor.

  • jdun1911

    Some of you reading this probably wondering do I have to check headspace on an AR15?

    No not in an AR15 with a standard BCG. Headspacing is done in the barrel making process. It either work or it don’t.

    It is almost impossible for the AR15 too shoot out of battery. You have a better chance of winning the Mega Million then a KB! due to out of battery issue.

    I recommend BCM because it comes with an upgraded extractor. It will comes in handy if you decide to use it in upper that has 10.5″ barrel or less.



    This thread should answer most of your questions.

  • bp

    Just a heads-up, M4 ramps aren’t a feature any more. Units being shipped recently had hand-filed feed ramps and other QC problems widely talked about on ar15.com. I’m happy with mine despite the feed ramp jobs, DSA chimed in and will not be cutting any more feed ramps on new ones.


  • The 53 page thread at arfcom reports that this upper will feed cheep and quality ammo flawlessly with a number of bcg’s. The actual owners of this this gun that know how to test it report accurate groups. They no longer offer costume machined ramps because people did not realize the value of such upgrades.
    Sincerely Shawn