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6.5 Grendel Assembled Complete Upper

(56 customer reviews)

From:  $699.00

Your 6.5 Grendel 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.

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.

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.)

At the bottom of this page we’ve included in-depth descriptions of various components as well videos and FAQ’s.

SAVE! Get up to $250 off any Complete Upper with the purchase of an Optic

James M.
Excellent fit and quality. I was very impressed with the workmanship and how fast my order was processed.
Mike H.
This is a great upper. I like that you get the option to configure it yourself. You get to add the things that you would upgrade later, thus saving money in the long run.
Nick F.
Fast shipping and a product that just works. Very accurate with Hornady 123gr ELD-M, easy to get groups under 1″ at 100yds, and an absolute blast to use at the range!

6.5 Grendel Barrels

Your barrel is the heart of the system. We offer 16″, 18″, 19″ 20″, and 22″ lengths 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.

  • Finishes: Choose between Uncoated Stainless, Black Cerakote, or a Bead Blasted Stainless finish.

  • Fluting: Most Lengths available in a Non-Fluted, classic profile or with Straight Flutes for weight savings.

Specifications

  • Liberty Barrels® made by Satern®
  • 6.5 Grendel
  • 416R Stainless Steel
  • Medium Contour
  • 1-8 Twist 5R Rifling
  • Mid Length Gas (16″ & 18″)
  • Rifle Length Gas (18″, 19″, 20″ & 22″) 
  • 5/8×24 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.

  • Radiused Extractor Geometry: We avoid the “sharp fangs” found on most extractors. By having smooth corners on the extractor claw, we prevent the steel from digging into the brass case rim, ensuring the ejector can “kick” the brass out at the exact right microsecond for a clean ejection cycle.

  • Built to Last: Our bolts are machined from 9310 Steel, shot-peened for fatigue resistance, and Magnetic Particle Inspected (MPI).

Professional Grade Finishes

We offer four distinct finishes, each offering a significant upgrade over the old Mil-Spec phosphate in terms of lubricity, hardness, and ease of cleaning.


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.

Nickel Boron (NiB)

  • Surface Hardness: ~1800 HV (Vickers)

  • The Process: UCT EXO® (High Boron content).

  • The Benefit: An extremely hard, durable finish with a very low friction coefficient. It’s smooth and wipes clean easily.

DLC (Diamond-Like Carbon)

  • Surface Hardness: ~2300 HV (Vickers)

  • The Process: Next-level Plasma Enhanced Chemical Vapor Deposition (PECVD)

  • The Benefit: High hardness, Excellent abrasive wear resistance, Low thermal conductivity, Ultra-Low friction level.

P51+ High Polish Black

  • Surface Hardness: ~2300 HV (Vickers)
  • The Benefit: The same attributes of our DLC, but it receives extra polishing cycles to give it an EXTREMELY smooth and deep, black finish. 

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: 6.5 Grendel / 6mm ARC / .22 ARC

  • 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.

It depends on how you define “optimal.” In theory, if it takes 24″–26″ to get 100% of the powder burn inside the bore, then anything less is technically a compromise. But for most of us, carrying a “musket” in the field isn’t exactly optimal, either.

Ultimately, the right length comes down to your specific requirements. For example:

  • If you’re running a suppressor, getting in and out of a side-by-side, or trekking long distances, the portability of an 18″ barrel is hard to beat.

  • If you’re calling coyotes a couple hundred yards from the truck and shooting off a tripod, you might prioritize the higher velocity and flatter trajectory of a 22″ barrel over weight savings.

Choose the length that fits how you actually hunt, not the one that strangers on the internet tell you is “optimal.”

Yes. You choose the components above and we assemble and test fire with those parts. 

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.

Velocity differences between different length barrels can vary somewhat depending on the load and how quickly a specific powder burns. In our testing, we generally see ~ 25 fps of velocity gained per inch of barrel length between 16″ and 22″ with the 6.5 Grendel.

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. 

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.

When it comes to choosing a handguard’s length, a lot of it is personal preference. Here are a few things to consdier though:

  • You will want 14″ or longer to cover a rifle length gas system. 13″ or less is best for mid length gas.
  • The 14″v.2 and 15.3″v.1 & v.3 just cover the gas block on a rifle length gassed barrel, so that should give you an idea of how much barrel will be showing. 
  • For unsuppressed rifles, showing 3″-4″ of barrel is the most popular look. For example, a 17″ handguard on 20″ barrel. On suppressed rifles, since a suppressor almost looks like an “extension” of the barrel, a lot of guys go a bit longer, for example, a 17″ handguard on an 18″ barrel. 
  • Our 15.3″ handguards had that specific length chosen with two things in mind. First, to cover a rifle length gas system. Second, to still allow the direct threading of a suppressor when installed with a 16″ barrel. 

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56 reviews for 6.5 Grendel Assembled Complete Upper

  1. Dsallee

    The machining, fit and finish are very high quality. On the first outing to the range I shot a 5 shot group with bulk Hornady ammo at 100 yards with all rounds touching, just one ragged hole! I went to the range today for the second time out and shot a couple 1/2″ groups and most groups averaged right about an inch. Not only is the upper accurate, it has functioned flawlessly. Andy at Grendel Hunter is super great to work with and promptly answered all my questions. This upper is a super good deal and Grendel Hunter is a great company, I have recommended this upper to my friends.

  2. Meeker800 (verified owner)

    Received my upper at the beginning of the week, Great price and real fast shipping. It looks amazing. Just picked up some Hornady Black 123gn eld match ammo. Shot a 5 shot group and a 100yd that measured out 0.725. Highly recommend the upper. Thanks you guys!

  3. Rick (verified owner)

    My expectations were exceeded, the build quality is excellent, fits very well with the aero precision lower I build for this rifle, I went with the 18″ fluted and accuracy is better than I expected as well. With box match ammo I am easily sub 3/4 moa and often put holes into holes. The adjustable gas is also a plus, dialed right in for different ammo, runs like a sewing machine, almost no recoil (which was expected) and I can sit back and ring steel over and over again. A real joy to shoot, I can’t wait to take it out for some sheep/goat/deer here in Alaska.

  4. patrick (verified owner)

    Got this today put it on my lower went out shot 12 rds at 100yds and they were all kill shots. Super impressed with this upper the craftsmanship and the accuracy. This just replaced All my other rifles. Hands down best looking and shooting rifle i now own.Glad i went with the Grendel Hunter upper.

  5. seth shipp (verified owner)

    Bought this gun to use on hog hunting about 6 months ago. Couldn’t be happier with results I’ve gotten. A very accurate gun that always gets the job done. My Grendel hunter is also one of the more attractive guns I own.