Stern Defense SD 4in Mod4 M-LOK 4in Barrel 9mm Black Complete Upper Receiver Black SDINBRLKK
Stern Defense · Upper Receiver
No ratings yetBest price
$419.27at OpticsPlanet
In stock Sale checked Nov 3, 2026
Where to buy
| Store | Price | Availability | Buy | Add to build |
|---|---|---|---|---|
| OpticsPlanet Best price | $419.27Salechecked Nov 3, 2026 | In stock | Buy at OpticsPlanet | |
| MidwayUSA | $443.48checked Nov 3, 2026 | In stock | Buy at MidwayUSA | |
| Battlehawk Armory | $354.74Salechecked Nov 3, 2026 | Check store | Buy at Battlehawk 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: $419.27 at OpticsPlanet. Dashed line = out of stock. Tracking since Oct 12, 2026.
Show the prices as a table
| Store | Latest | Lowest | Highest |
|---|---|---|---|
| Battlehawk Armory | $354.74 | $347.64 | $354.74 |
| MidwayUSA | $443.48 | $443.48 | $443.48 |
| OpticsPlanet | $419.27 | $419.27 | $419.27 |
Since Oct 12, 2026.
About this part
The Stern Defense SD 4in Mod4 M-LOK 4in Barrel 9mm Black Complete Upper Receiver Black SDINBRLKK is an AR-9 complete upper receiver from Stern Defense. It's sold by 3 stores (2 in stock), from $354.74 to $443.48. The lowest in-stock price in the last 30 days was $419.27 at OpticsPlanet.
Fits and works with
- Caliber
- 9mm · Shop matching ammo
- Bolt
- 9mm · Bolt carrier groups
- Barrel length
- 4" · Handguards
- Handguard length
- 4" · Barrels
Specifications
- Manufacturer
- Stern Defense
- Color
- Black
- Type
- Complete
- Platform
- AR-9
- Caliber
- 9mm
From the manufacturer
Stern Defense SD 4in Mod4 M-Lok 4in Barrel 9mm Black Complete Upper Receiver Black SDINBRLKK. ) Stern Defense 4 inch 9mm barrel. SD MBC 9MM Blast Can. Stern Defense assembled upper receiver with dust cover and forward assist. Stern Defense SD BU9 Glock cut bolt. SD CH1 enhanced charging handle. Will come assembled. Information: Handguard. The free float M-LOK handguard from Stern Defense offers excellent ergonomics while remaining lightweight and strong. This handguard is M-LOK compatible to accept your favorite attachments. Features a secure clamp on mounting system that ensures that the handguard remains in place even under heavy abuse sustained full auto fire and shooting prone from a bi-pod. Machined from 6061 aircraft grade aluminum and hard-coat anodized for longevity and durability. These handguards also feature quick disconnect swivel holes. Also Included Barrel Nut and Bolts. Specifications for Stern Defense SD Mod4 M-Lok 9mm Complete Upper Receiver: Manufacturer: Stern Defense Caliber: 9mm Luger Barrel Length: 4 in Barrel Twist Rate: 1-10 Muzzle Device: Muzzle Brake Finish: Matte Color: Black Fabric/Material: Melonite Magazine Included: No Condition: New Additional Features: Threaded .5-36 Features of Stern Defense SD Mod4 M-Lok 9mm Complete Upper Receiver Barrel length is measured in overall length from breech to muzzle. Caliber: 9mm. Length: 4 Inches. Threaded .5-36. 1:10 TWIST. 4150 Chrome-moly steel. Melonite coating. Package Contents: Stern Defense SD Mod4 M-Lok 9mm Complete Upper Receiver Stern Defense SDINBRLKK: SD 4in Mod4 M-Lok 4in Barrel 9mm Black Complete Upper Receiver Black
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