Mid State Firearms 16″ .223 Wylde AR-15 Upper Receiver Assembly
A well-built AR-15 upper is more than a collection of parts. The components need to work together, the gas system needs to be properly assembled and correctly aligned, and the finished upper needs to meet the standards you expect when you put it on your rifle.
That’s where Mid State Firearms comes in.
Mid State Firearms has been building quality AR-15 uppers since 2014, with an emphasis on proper assembly, quality components, and attention to the details that matter. This 16″ .223 Wylde upper combines a 1:8 twist spiral-fluted 416R stainless steel barrel with an FDE PVD finish, a mid-length gas system, a rigid 13.7″ wedge-lock M-LOK handguard, and a lightweight 7075-T6 aluminum upper receiver.
The result is a distinctive, purpose-built upper that combines a carefully selected component package with Mid State Firearms’ assembly and quality-control standards.
Built by Mid State Firearms
We believe the difference between a box of components and a properly assembled upper matters.
Our uppers are assembled by Mid State Firearms rather than simply being packaged together from loose components. We pay attention to barrel installation, gas system alignment, gas block positioning, fastener installation, and the overall fit and function of the assembly.
Optional BCG? We test it.
When you add the optional bolt carrier group to this upper, Mid State Firearms test-fires the completed upper with that exact BCG. This allows us to verify headspace and function with the actual bolt carrier group being supplied with your upper rather than treating the BCG as an unrelated accessory.
That means your upper arrives assembled and tested as a system—not simply as a bunch of parts.
Barrel & Gas System
At the heart of the upper is a 16″ 416R stainless steel barrel with a distinctive spiral-fluted profile and FDE PVD finish.
The .223 Wylde chamber is designed for use with both .223 Remington and 5.56 NATO ammunition. The 1:8 twist rate is a versatile choice for the AR-15 platform and accommodates a broad range of commonly used .223/5.56 bullet weights.
The mid-length gas system is a popular configuration for a 16″ AR-15 barrel. The steel .750″ low-profile gas block is installed on a barrel that is dimpled to provide a positive reference for the gas block set screw.
The gas system uses a stainless steel mid-length gas tube.
Upper Receiver
The receiver is a tan anodized 7075-T6 aluminum upper receiver with a streamlined no-forward-assist configuration.
It features:
- 7075-T6 aluminum construction
- Tan anodized finish
- No forward assist
- Dust cover
- M4 feed ramps
The no-forward-assist configuration provides a clean, streamlined appearance while retaining the standard dust cover and M4 feed ramp configuration.
RG2-S Wedge-Lock Handguard
The upper is fitted with a 13.7″ RG2-S Wedge-Lock M-LOK rail system finished in anodized black.
The wedge-lock design provides a rigid handguard mounting system, while the M-LOK interface provides a broad range of options for attaching compatible accessories.
The 13.7″ handguard pairs well with the 16″ barrel, providing substantial usable rail space while leaving the muzzle device exposed.
OTX 3-Prong Muzzle Device
The muzzle is fitted with an OTX 3-prong muzzle device on standard 1/2×28 threads. Pair it with a Castle Blast shield for optimum modularity.
The compact 3-prong design complements the upper’s overall configuration while providing a clean transition at the muzzle.
Specifications
| Feature | Specification |
|---|---|
| Platform | AR-15 |
| Caliber | .223 Wylde |
| Barrel Length | 16″ |
| Barrel Material | 416R Stainless Steel |
| Barrel Finish | FDE PVD |
| Barrel Profile | Spiral Fluted |
| Twist Rate | 1:8 |
| Gas System | Mid-Length |
| Gas Block | .750″ Steel Low Profile |
| Gas Block Retention | Barrel Dimpled for Set Screw |
| Gas Tube | Stainless Steel, Mid-Length |
| Upper Receiver | 7075-T6 Aluminum |
| Upper Finish | Tan / Clear Anodized |
| Forward Assist | None |
| Dust Cover | Yes |
| Feed Ramps | M4 |
| Handguard | RG2-S Wedge-Lock M-LOK |
| Handguard Length | 13.7″ |
| Handguard Finish | Anodized Black |
| Muzzle Device | OTX 3-Prong |
| Muzzle Threads | 1/2×28 |
| BCG | Optional |
Why Buy a Mid State Firearms Upper?
When you’re spending around $700 on an AR-15 upper, you’re not just paying for a barrel, handguard, receiver, and muzzle device. You’re paying for the assembly behind those components.
Mid State Firearms has been in business since 2014, building AR-15 components and complete uppers for customers who expect their equipment to be assembled correctly and supported by a real company.
We stand behind our work with a limited lifetime warranty and take the assembly process seriously. Our goal isn’t simply to get an upper out the door—it’s to deliver a properly assembled product that you can install on your lower and have confidence in.
And when you choose the optional BCG, we go one step further by test-firing the completed upper with that specific BCG to verify headspace and function before it leaves Mid State Firearms.
That’s the kind of detail that matters when your upper isn’t just a collection of parts—it’s a finished assembly.
Built by Mid State Firearms. Built to be used.
Package Contents
- Mid State Firearms 16″ .223 Wylde upper receiver assembly
- 416R stainless steel spiral-fluted barrel with FDE PVD finish
- Tan anodized 7075-T6 upper receiver
- 13.7″ RG2-S Wedge-Lock M-LOK handguard
- .750″ steel low-profile gas block
- Stainless steel mid-length gas tube
- OTX 3-prong muzzle device
- Dust cover
- M4 feed ramps
- Optional: Bolt carrier group
Note: Bolt carrier group is optional unless otherwise specified in the product configuration. Firearm, ammunition, and component compatibility are the responsibility of the end user. Always follow applicable federal, state, and local laws and regulations.
sound of freedom – This was a great set up. I loved being able to customize the set up. Only issue I had was my own fault as a newb to building these. I used a heavy barrel in a slim hand guard. It makes adding attachments tough with clearances. Hoping someday to also get an AR10 from here.