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U.S. Arms M4 UTAW Gen II Champion 5.56/.223 Rifle

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  • Your order will ship only to a Federal Firearms License holder.
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The U.S. Arms Company M4 UTAW Gen II Champion series is the most advanced rifle we offer. This weapon system has it all. Looks, dependability, and accuracy. We stand behind our name on every rifle and weapon system we manufacture. However, this specific rifle is the main platform used to showcase our bleeding edge technology and what we are capable of at U.S. Arms Company. This weapons system is offered in .223 Wylde (5.56/.223).

The Gen II Champion Series can be configured with a black anodize or a multitude of Cerakote options for the handguard, trigger guard and receiver set. This rifle includes our patented “Cam Lock” lower receiver so that you get the tightest receiver fit on the market. The Cam Lock lower receiver will also fit any mil-spec upper assembly. We are “Home of the World’s Tightest Receivers”.

The M4 UTAW rifle series is available in multiple colors and finishes:

  • Anodized Black
  • Cerakote Black
  • Cerakote Chocolate Brown
  • Cerakote Gun Metal Gray
  • Cerakote Woodland Camo
  • Cerakote Arctic Camo
  • Cerakote Alpine Dark

The barrel installed in this weapon system is constructed from a 416R Stainless Steel. The barrel is then fluted, bead blasted, and equipped with a nickel boron barrel extension. As a result of using a nickel boron extension and a nickel boron bolt carrier group, the shooter experiences extremely smooth cycling. To aid in the best shooting experience, the rifle also comes standard with a state of the art gas system consisting of an SLR .750” adjustable titanium gas block along with an SLR mid length Melonite gas tube. We are proud to run TriggerTech triggers in our Champion Series rifle line up. Our M4 UTAW Gen II Champion series rifle comes equipped with a trigger second to none in its class; the TriggerTech Diamond 2-Stage, which is easily adjustable from 1.5lbs to 4.0lbs without removing the trigger from the lower receiver. This gives the shooter a custom, crisp and clean trigger break every time the weapon system is fired.  Other additions to this series are Magpul MBUS Pro steel iron sights, a Magpul ACS buttstock, an ambidextrous Radian Raptor charging handle, Magpul ASAP QD Backplate, and the option of configuring your rifle with the M-905 Talon Muzzle Brake or the Strike Industries Venom flash hider. This is then all packaged in a hard U.S. Arms Company SKB single rifle case.

The U.S. Arms M4 UTAW Gen II Champion series rifle is meant to set you apart from the crowd in looks and performance. The M4 UTAW Gen II Champion series rifle is the highest level of perfection from U.S. Arms Company. This weapon system provides a signature look and design aesthetic that’s unlike any other in the market, while giving the shooter highest level of confidence and flawless performance in gun competitions, sport shooting, and defense for years to come.



  • 1

    Muzzle Device

    Paired with our M4 UTAW Gen II Champion, our M-905 Talon muzzle brake which reduces recoil by 94%. However a flash hider can also be equipped during checkout.

  • 2


    We utilize a match grade, .223 Wylde, 416R SS, 1:7 fluted barrel. This barrel is guaranteed to shoot 1 MOA as a result of the chamber being individually cut to the BCG paired with this weapon system.

  • 3


    The handguard is a 15″ aluminum free-floating handguard with a full-length top Picatinny rail, side and bottom M-LOK slots, and two QD mount points.

  • 4

    Receiver Set

    The Receiver set is constructed from 7075-T6 aluminum and is a mated set with the patented Cam-Lock technology by U.S. Arms Company.

  • 5


    The best rifle deserves the best trigger; the TriggerTech Diamond 2-Stage PVD Curved. This trigger is adjustable from 1.5lbs -4.0lbs.

  • 6


    Cam-Lock is what the name infers; a locking system. Cam-Lock is superior to “wedge systems” that push the receivers apart and out of alignment. Cam-Lock locks the mating surfaces of the upper and lower receiver together eliminating any play in the receiver set.

  • 7


    Ready to shoot straight out the box with the Magpul MBUS Pro Steel Back up Sights. Grab some ammo and you can hit the range on the same day you pick up one of the M4 UTAW Gen II Champions.

  • 8


    Stay locked in and comfortable with confidence with the MAGPUL ACS Carbine stock which comes equipped with a storage compartment for tools and additional battery compartments.



.223 Wylde (5.56 NATO / .223 Rem)

Barrel Length

16-inch, 20-inch

Barrel Profile

Medium with Flutes

Barrel Rifling

1:7" (178mm)

Barrel Construction

Cold Hammer Forged 416R Stainless Steel

Muzzle Thread

1 / 2 × 28 threads per inch

Gas System

Mid-Length (with 16-inch barrel)
Rifle-Length (with 20-inch barrel)

Mounting System



6.79 lbs when equipped with the M-905 Talon Muzzle Brake


35.6" – 39.4"


Two 30-round Lancer L5-AWM Black

Lower Receiver

U.S. Arms Cam-Lock Billet

Product Benefits

  • Designed and engineered to allow significant weight reduction without sacrificing strength
  • Shoots 3/4 or less with match grade ammunition and Cam-Lock lower receiver
  • Machined to aerospace tolerances in a ISO certified aerospace facility

Details and Build Materials

  • Receiver Set: 7075-T6 aluminum mated set with Cam-Lock technology by U.S. Arms
  • Trigger: TriggerTech Diamond 2-Stage PVD Curved
  • Safety: TrigerTech Ambidextrous AR Safety 45-90
  • Hand Grip: ERGO Grips Flat Top Tactical SUREGRIP
  • Buffer Assembly: Mil-Spec 6 position aluminum buffer tube with H1 buffer
  • Buttstock: MAGPUL ACS Carbine stock
  • Bolt Carrier Group: U.S. Arms Nickel boron M16/4 full-auto, MP tested, with properly staked gas key
  • Charge Handle: Radian Raptor Ambidextrous
  • Handguard: 15″ aluminum free-floating with full-length top Picatinny rail, side and top M-LOK slots, and side QD mount points
  • Sights: MAGPUL MBUS Pro front and rear
  • Barrel: 16″ or 20″Cold Hammer Forged 416R, 6 groove, 1:7 twist, fluted with a nickel boron extension and match grade headspace.
  • Gas System: SLR low profile titanium .750″ gas block and SLR mid-length Melonite gas tube
  • Muzzle Device: Your choice of U.S. Arms M-905 Talon Muzzle Brake or Strike Industries Venom flash hider
  • Magazine: 2 Lancer Systems L5AWM 30 round magazines
  • Case: SKB iSeries 4909-5 single rifle case