Rock River Arms Completed Upper Receiver .223/5.56mm 16 Inch Barrel Carbine Profile 1/2-28 Thread Car Handguard A2 Flash Hide w/Gas Block Black
$486.99 at MidwayUSA · 2 stores
In stock
Best price
$489.99at OpticsPlanet
In stock Sale Lowest in 30 dayschecked Nov 12, 2026
Fits and works with
- Caliber
- 5.56 / .223 · Shop matching ammo
- Bolt
- Standard AR-15 (5.56 / 300 BLK / .350 Legend) · Bolt carrier groups
- Barrel length
- 16.1" · Handguards
Specifications
- Manufacturer
- CMMG
- Color
- Black
- Type
- Complete
- Platform
- AR-15
- Caliber
- 5.56 mm NATO
- Barrel length
- 16.1"
- Twist rate
- 1:7
- Weight
- 57.6 oz
Where to buy
| Store | Price | Availability | Buy | Add to build |
|---|---|---|---|---|
| OpticsPlanet Best price | $489.99Salechecked Nov 12, 2026 | In stock | Buy at OpticsPlanet | |
| Ammunition Depot | $493.49checked Nov 13, 2026 | In stock | Buy at Ammunition Depot | |
| Sportsman's Warehouse | $559.95checked Nov 13, 2026 | In stock | Buy at Sportsman's Warehouse | |
| Brownells 17.76% off · ends Nov 15 · exclusions apply | $595.38checked Nov 13, 2026 | In stock | Buy at Brownells | |
| Dirty Bird | $399.95Salechecked Nov 12, 2026 | Check store | Buy at Dirty Bird | |
| GrabAGun | $469.99checked Nov 12, 2026 | Check store | Buy at GrabAGun | |
| AR15Discounts 5% off | $499.00checked Nov 12, 2026 | Check store | Buy at AR15Discounts | |
| Palmetto State Armory | $525.99checked Nov 13, 2026 | Check store | Buy at Palmetto State Armory |
Prices and availability change often, so confirm on the store's site before you buy. We may earn a commission from these links.
Price history
Lowest in-stock price in the last 30 days: $489.99 at OpticsPlanet. Dashed line = out of stock. Tracking since Sep 27, 2026.
Show the prices as a table
| Store | Latest | Lowest | Highest |
|---|---|---|---|
| AR15Discounts | $499.00 | $499.00 | $499.00 |
| Ammunition Depot | $493.49 | $493.49 | $493.49 |
| Brownells | $595.38 | $595.38 | $595.38 |
| Dirty Bird | $399.95 | $399.95 | $399.95 |
| GrabAGun | $469.99 | $469.99 | $469.99 |
| OpticsPlanet | $489.99 | $489.99 | $489.99 |
| Palmetto State Armory | $525.99 | $525.99 | $574.99 |
| Sportsman's Warehouse | $559.95 | $559.95 | $559.95 |
Since Sep 27, 2026.
About this part
The Resolute Mk4 5.56 NATO Assembled Upper Rcvr 16.1" Bbl Black is an AR-15 complete upper receiver from CMMG. It's sold by 8 stores (4 in stock), from $399.95 to $595.38. The lowest in-stock price in the last 30 days was $489.99 at OpticsPlanet.
From the manufacturer
CMMG RESOLUTE MK4 5.56X45MM NATO ASSEMBLED UPPER RECEIVER Top off your next build with this RESOLUTEA(R) Mk4 Upper Group. Chambered in 5.56x45mm, this upper group is a staple for any collection. This upper group does NOT include BCG or charging handle. SPECS Platform: Mk4 Caliber: 5.56x45mm Operating System: Direct Impingement Barrel Length: 16.1" Barrel Twist: 1:7 Barrel Contour: MT Barrel Material: 4140CM, SBN Muzzle Device: CMMG A2 Flash Hider Muzzle Thread: 1/2 x 28 Gas Port Location: Mid Gas Block: Non-Adjustable 0.750" Upper Receiver: Billet 6061 T6 Alu Mfg: Cmmg
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