5.56 NATO / .223 Wylde Assembled Complete Upper
From: $599.00
Your 5.56/.223 Wylde Upper. Your Way.
Most AR-15 complete uppers come with parts you’re just going to swap out as soon as you open the box. At Grendel Hunter, we don’t believe in making you pay for parts you’re just going to throw in a spare parts bin. Have it built your way from the beginning and skip the box of leftover parts.
How it Works
Our Custom Upper Builder lets you spec out your upper exactly how you want it from the start. We offer numerous options for barrels, handguards, BCG’s etc. The base price is for a complete, fully assembled upper. If you want to upgrade a component—like switching a mil-spec charging handle for an ambidextrous one—just select your preference and the total at the bottom of the page will update automatically.
A Note on BCG's
The base price includes a Bolt Carrier Group. However, if you already have a BCG for this caliber, we aren’t going to force you to buy another one. Selecting “None” for that component will give you a $100 discount at checkout.
(Please Note: This $100 discount is applied in the cart and will not be reflected in the “Grand Total” at the bottom of this builder page.)
Product Details
At the bottom of this page we’ve included in-depth descriptions of various components as well videos and FAQ’s.
Save with an Optics Bundle
SAVE! Get up to $250 off any Complete Upper with the purchase of an Optic
5.56 NATO & .223 Wylde Barrels
Your barrel is the heart of the system. We offer a 16″ M4 contour 5.56 NATO barrel as well as 16″ & 18″ lengths .223 Wylde barrels in a Medium Contour so you can find the perfect balance between velocity and portability for your application.
Material: 416R Stainless Steel for accuracy and durability. (M4 barrel is 4140 CMV)
Finishes: Choose between Uncoated Stainless and Black Cerakote finish for the .223 Wylde. The M4 barrel is a traditional Mag-phos.
Fluting: Available in a Non-Fluted, classic profile or with Straight Flutes for weight savings.
Specifications
- Liberty Barrels® made by Satern®
- 5.56 NATO & .223 Wylde
- 4140 CMV & 416R Stainless Steel
- M4 & Medium Contour
- 1-8 Twist 5R Rifling (M4 is 1-7 Twist 6 Groove)
- Mid Length Gas (M4 is Carbine)
- 1/2-28 Threads
- .750 Gas Block Journal
Grendel Hunter AR-15 Billet Upper Receivers
Forget standard, mass-produced mil-spec forgings. We designed our Grendel Hunter Billet uppers to move beyond the “basic” look of a standard AR. Billet allows us the design freedom to create sharper lines and a more modern aesthetic that you just can’t get from a forging.
We didn’t just design an upper; we designed a system. Our uppers and handguards are engineered to match up in an almost monolithic way, creating a seamless, integrated look.
Slick Side: For the minimalist—no forward assist, shell deflector, or dust cover.
Traditional: Includes all standard features for those who want a classic style upper.
Premium Finishing: Available in Black Hardcoat Anodized, Magpul FDE Cerakote, and Magpul OD Green Cerakote. Note: All Cerakoted uppers are anodized on the interior for maximum durability and smooth cycling.
Specifications
- 6061 T-6 (Slick Side Upper) or 7075 T-6 Aluminum (Traditional Upper)
- M4 Feed ramps
- .250 takedown pin holes
- Forward Assist with threaded roll pin (Traditional Upper)
- Dust Cover (Traditional Upper)
Grendel Hunter AR-15 Handguards: Form & Function
Every Grendel Hunter handguard is designed to integrate seamlessly with our billet uppers, creating a near-monolithic look and a rock-solid mounting platform. While they share the same rugged DNA, each version has a unique style.
Built-In Standards across all models:
Material: Lightweight, high-strength 6061-T6 Aluminum.
Rock-Solid Lockup: A heavy-duty Steel Barrel Nut and Steel Retention System ensure your rail doesn’t shift, even with heavy use.
Anti-Rotation Tabs: Integrated tabs prevent the rail from twisting under torque.
Slim Profile: A 1.3″ inside diameter provides a modern, ergonomic “C-clamp” grip and a sleek look.
- Premium Finishing: Available in Black Hardcoat Anodized, Magpul FDE Cerakote, and Magpul OD Green Cerakote
Which Version is Right for Your Build?
V1:
Front Profile: Aggressive Slant-Cut
Top Rail: Competition Style (Rails at front and back only)
M-LOK Slots: Sides and Bottom
Weight: Our Lightest Option
The V1 is our lightest handguard. By utilizing a competition-style top rail and a sleek slant-cut front, we’ve shed every unnecessary ounce without sacrificing mounting space.
V2:
Front Profile: Traditional Squared-Off
Top Rail: Competition Style (Rails at front and back only)
M-LOK Slots: Sides and Bottom
Weight: Balanced
If you prefer a more traditional look, the V2 features a squared-off front end. It maintains the competition-style top rail for weight savings.
V3:
Front Profile: Aggressive Slant-Cut
Top Rail: Full Picatinny (Continuous top rail)
M-LOK Slots: Full 360° (All sides)
Weight: Built for utility, but our heaviest option
The V3 is our most capable rail. It features a full-length Picatinny top rail and M-LOK slots surrounding the entire circumference. This is the go-to choice for hunters running thermal clip-ons, IR illuminators, or side-mounted accessories.
The Grendel Hunter BCG: Precision-Tuned Reliability
Headspace Check: We perform a manual headspace check for every upper using the specific barrel and bolt you’ve selected.
Optimized Extractor Tension: Excessive tension is a leading cause of malfunctions and extractor failure. We are meticulous about our extractor tension being at the “sweet spot”—ensuring reliable cycling without putting unnecessary stress on the steel.
Built to Last: Our bolts are machined from 9310 Steel, shot-peened for fatigue resistance, and Magnetic Particle Inspected (MPI).
BCG Finish Specifications
Black Nitride
Surface Hardness: ~740 HV (Vickers)
The Process: A salt-bath thermo-chemical treatment that hardens the steel.
The Benefit: Far more durable and smoother than original Mil-Spec magnesium phosphate with excellent corrosion resistance.
BCG Technical Specifications:
Carrier: M16 Auto Profile (8620 Steel) for smooth cycling and increased mass.
Gas Key: 4130 Steel with properly staked Grade 8 fasteners.
Bolt: 5.56 NATO
Small Parts: 4140 Steel Cam Pin and Hard Chrome Firing Pin.
Grendel Hunter Gas Blocks
We exclusively use adjustable blocks in our uppers. With the explosion in popularity that suppressors have enjoyed in recent years, it just makes sense to have the ability to tune the gas. There are two models to choose from.
Note: Every upper is test-fired and shipped pre-set for reliable unsuppressed firing.
GH .750 Adjustable (Set & Forget)
Best For: Those who don’t plan to suppress or shooters who will suppress and want to tune their gas once and leave it. Generally requires handguard removal for adjustment since cutouts in handguards don’t always align with the adjustment screw. Handguard removal is as simple as removing two hex bolts, but it is an extra step.
Design: Side-access adjustment (1/16” Hex) with a front-facing locking screw.
Material: 4140 Steel with a Black Nitride finish.
GH .750 Click Adjustable (Premium)
Best For: Those who suppress or who like to really fine tune their rifles.
Design: Ball-detent system with 22 audible clicks of adjustment across the gas port and zero-shutoff.
Ease of Use: Front-access adjustment screw (1/8″ Hex) allows for tuning without removing the handguard.
Performance: Eliminates the “violent” over-gassed cycle common with suppressors, reducing carrier speed and heat.
Materials: 4140 PHT or 303 Stainless Steel.
Finishes: Black Nitride, Stainless, or Bead Blasted Stainless.
Will my upper come assembled and test fired?
Yes. You choose the components above and we assemble and test fire with those parts.
Will my upper receive a headspace check?
Yes. For every upper we build, we take the specific barrel and bolt the customer has selected and perform a headspace check prior to assembly.
What is the lead time on an upper?
We ship the same or next business day. Since our website has a live inventory and we only sell things that actually exist on our shelves, we do not have lead times.
If a specific component I want is out of stock, can I place the order anyway?
Unfortunately, we do not accept backorders. It’s Grendel Hunter’s policy to only take a customer’s money for things that exist.
If a specific component is out of stock, you can go to that item’s individual product page and join the “Back in Stock” email notification list.
Matt –
Great website. Easy to put together the components you need
Steve Starnes (verified owner) –
Great components, great guy! I have 2 grendels and 1 5.56 all uppers from Grendel Hunter. I am extremely impressed with the quality of the products and the level of service provided! The turnaround time is superior to anyone else! The attention to detail is superior to anyone else! The accuracy if the 3 uppers I have is under 1/2 MOA at 100 yards! All chambers are on the snug side of tolerance. I suspect that lends to the accuracy I’m getting. I’m so pleased with the performance, I’m in the process of ordering another 5.56!
Kyle Bush –
Easy to put together
Brad McCombs –
I don’t know that I can rate the rifle upper but I do love your website and being able to build my own rifle feature.
Adam Rogers –
Andy is the best military discount the sites you can trust are going downhill this is the most well made well crafted uppers on the market