Shipping to California
- Status: Complete upper with a barrel. Not a serialized firearm, but we ship it to a licensed dealer only.
- Delivery: Ships to WBT in La Mesa or to the California gun store you choose; select your dealer at checkout. Not shipped to home addresses.
- Learn more: Featureless or fixed magazine: which fits your build · FAQ
About this upper
Primary Weapons Systems MK109 Mod 1-M, Upper Receiver is an upper receiver chambered in .300 Blackout. Finish: Black.
Manufacturer details
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" barrel length provides excellent reliability with a range of ammunition and still function well, with or without a suppressor and without the need for an adjustable gas system. The MK109 includes the Triad 30 Compensator.
Features
- PRIMARY WEAPONS AR-15 MK1 MOD 1-M UPPER RECEIVER ASSEMBLY 300 BLACKOUT M-LOK
- FEATURES
- Long stroke piston system
- M-LOK handguards
- Includes Radian Raptor Charging Handle
- 1:6 barrel twist rate
Specifications
- Brand: Primary Weapons Systems
- Caliber: .300 Blackout
- Finish / color: Black
- Fits: AR-15
- Manufacturer part #: MK1-M1U-300BLK-9
- UPC: 811154033451
Buying from WBT Guns
- Delivery: Complete uppers ship to a licensed dealer only. Free pickup at our La Mesa store, or select the California gun store you want it sent to at checkout.
- Payment: Pay in full, put 50% down with the balance due in 14 days, or finance with Credova.
- Questions: Call (619) 667-9453 or email sales@wbtguns.com. FAQ
WBT Guns is family-owned in La Mesa, California, and has shipped parts and receivers to California buyers since 2012.
A note on accuracy. We work hard to keep every listing correct, but specifications, images and compliance details come from many sources and can contain errors or change without notice. Images may show a configuration that is not California-legal. If a detail on this page matters to your decision, call us and we will confirm it against the actual firearm before you order. The compliance information here is general in nature and is not legal advice; California and local laws change, and the configuration described is confirmed at the time of sale. All sales are subject to applicable federal, state and local law and to the buyer's eligibility to purchase.
