Mk109 Mod 2-M 300 AAC Blackout 9.75" Bbl Complete Upper
$1,399.95 at MidwayUSA · 5 stores
In stock
M-LOK Mk109 Mod 1-M 300BLK Upper Receiver W/9.75" Bbl
Primary Weapons Systems · Upper Receiver
No ratings yetBest price
$1,129.95at Brownells
In stock checked Oct 21, 2026
Where to buy
| Store | Price | Availability | Buy | Add to build |
|---|---|---|---|---|
| Brownells Best price | $1,129.95checked Oct 21, 2026 | In stock | Buy at Brownells | |
| OpticsPlanet | $1,129.95Salechecked Oct 21, 2026 | In stock | Buy at OpticsPlanet | |
| MidwayUSA | $1,209.95checked Oct 21, 2026 | In stock | Buy at MidwayUSA | |
| Battlehawk Armory | $1,129.95Salechecked Oct 21, 2026 | Check store | Buy at Battlehawk Armory | |
| Palmetto State Armory | $1,209.99checked Oct 14, 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: $1,129.95 at Brownells. Dashed line = out of stock. Tracking since Sep 27, 2026.
Show the prices as a table
| Store | Latest | Lowest | Highest |
|---|---|---|---|
| Battlehawk Armory | $1,129.95 | $1,129.95 | $1,129.95 |
| Brownells | $1,129.95 | $1,129.95 | $1,129.95 |
| MidwayUSA | $1,209.95 | $1,209.95 | $1,209.95 |
| OpticsPlanet | $1,129.95 | $1,129.95 | $1,129.95 |
| Palmetto State Armory | — | $1,209.99 | $1,209.99 |
Since Sep 27, 2026.
About this part
The M-LOK Mk109 Mod 1-M 300BLK Upper Receiver W/9.75" Bbl is a 300 Blackout upper receiver from Primary Weapons Systems. It's sold by 5 stores (3 in stock), from $1,129.95 to $1,209.99. The lowest in-stock price in the last 30 days was $1,129.95 at Brownells.
Fits and works with
- Caliber
- 300 Blackout · Shop matching ammo
- Bolt
- Standard AR-15 (5.56 / 300 BLK / .350 Legend) · Bolt carrier groups
Specifications
- Manufacturer
- Primary Weapons Systems
- Platform
- AR-15
- Caliber
- 300 Blackout
From the manufacturer
PRIMARY WEAPONS AR-15 MK1 MOD 1-M UPPER RECEIVER ASSEMBLY 300 BLACKOUT M-LOK The Primary Weapons Systems MK1 MOD 1-M line of upper receivers feature the PWS long stroke piston system. Internally, this line offers the tried and true system that PWS owners have grown to know and love. Featuring a free-float MLOK handguard, forward assist controls, and a more true to mil-spec design, the MK1 MOD 1-M line is a go-to for not only civilians, but also Law Enforcement. With the fully forged upper, the MK1 MOD 1-M is a no-nonsense tool for when you need a high value option that is relentless and unstoppable. PWS bring back the original MK109 in 300BLK. The 9.75" Mfg: Primary Weapons
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