The Best 6.5 Grendel Uppers

Michael Crites


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best 6.5 grendel uppers

This article is part of our Guide to Everything AR

The 6.5 Grendel has become one of the more popular choices for long-range shooters in the last several years. When compared to the 5.56mm, the larger round of the 6.5 adds long-range oomph where the 5.56 NATO can fail to impress.

In this piece, we’re going to cover some of the best 6.5 Grendel upper receivers on the market, with a dive into Palmetto State Armory in particular, which has gone deep into Grendel with their line of uppers. We’ll review the benefits of a few different versions of their offerings as well as other top options.

And because nobody is satisfied with a list of products, we also take a look at the origins of the 6.5 Grendel, the history of the round, its benefits and shortcomings, and some suggestions for how to choose the best 6.5 uppers for your needs.

In This Article:

6.5 Grendel Upper Comparison

Below is my list of 6.5 Grendel upper recommendations. I list the best choices in terms of value, performance, design, and cost.

Click on the name to head to the product page, read reviews and check prices or skip ahead to the list of uppers.

6.5 Grendel Upper Recommendations

1. Palmetto State Armory 6.5 Grendel Upper

This 18” Palmetto State Armory upper gives you a barrel length that enables the 6.5 Grendel to be its most flexible: able to reach out at long range, but still short enough to be a fairly mobile platform.

What We Liked:

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These barrels come with a 1:8 twist rate, which is ideal for stabilizing the 6.5 Grendel, paired with a low-profile adjustable gas block to prevent limitations on optic mounting. 

The major value add here is PSA bundling the upper with a Vortex Strike Eagle 1-8x24mm optic, which is a nice touch if you’re interested in shooting the Grendel at long range (as any reasonable human would be).

2. CMMG 6.5 Grendel Upper Receiver

CMMG also has an excellent series of uppers chambered in 6.5 Grendel. The receivers themselves are hard-coat anodized to make sure that they last for years, and have some features that make sense on any AR.

The inclusion of a brass deflector and dust cover — both of which can be hard to come by on more budget-friendly rifles — are present here.

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While you can spec these out any way you like, the 12.5-inch barrel with an 11-inch handguard and an SV Brake is a unique set-up. The 12.5-inch barrel with a 1:8 twist the 6.5 Grendel could make for a defensive-oriented build, but bear in mind is likely to make a heck of a bang, which should be tamed with the brake.

You’ll also need to pair it with a brace and pistol lower to keep in the good graces of the ATF.

3. Palmetto State Armory 6.5 Grendel Upper Receiver

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To take advantage of the long-distance capabilities of the round, PSA also offers a 20-inch rifle length 6.5 Grendel upper receiver. This is where the Grendel really shines: the extra barrel length means you’ll be getting every bit of velocity out of the round — and driving tacks at considerable distance.

That longer barrel, like the other PSA offerings, has free-floating rails, and the handguard offers you tons of Picatinny rail space to mount any kind of optics or accessories you might want.

Additionally, the barrel is finished out with your standard A2 style muzzle device, which can, of course, be replaced with any muzzle device of your choosing.

4. Radical Firearms 6.5 Grendel Upper Receiver

Radical firearms has an excellent reputation for their barrels, so seeing them embrace the Grendel is great news.

These come with a stainless 24-inch match-grade barrel, a pepper pot style muzzle brake, and your choice of handguard — M-LOK, KeyMod or Parallelogram — to keep things consistent with the rest of your collection.

The great thing about the 6.5 Grendel is that, aside from the barrel and bolt, everything else is standard, mil-spec AR15. These uppers give you a plug-and-play means of completing a build with a bare lower receiver or taking an existing AR in a new direction — but likely at a substantial cost savings over purchasing a separate rifle.

5. Palmetto State Armory 6.5 Grendel Pistol Kit

PSA’s kits come with everything you need but the lower receiver, and this 12-inch upper is paired with the parts kit to ensure you’ve got what you need to put it in place.

If your goal is to build a lightweight hunting gun that will work just as well in a truck or UTV, the 12-inch barrel will give you enough punch for any pest — be it groundhogs, coyotes, or hogs, and give you up to 400 yards of accuracy for things like deer. There are some important considerations though. 

The first is that the barrel is 12-inches long so you’ll be limited in terms of range to a few hundred yards. Second, you’ll need a brace rather than a stock for ATF compliance or get your short-barreled rifle (SBR) tax stamp.

If you have questions about how to navigate ATF compliance you probably shouldn’t be tacking together a pistol/SBR in the first place, but when in doubt consult a lawyer — because that ain’t us. 

6. Aagil Arms 6.5 Grendel Upper Receiver

Finally, we have to include one of the more, uh… interesting products we’ve seen in a while. This is a 6.5 Grendel upper with a flat top rail and comes in a hard-anodized coating. With a 16-inch barrel and mil-spec dimensions, there’s not much to see here, right?

Well, not so fast. This one comes in two paint jobs that caught our attention. The first is all black, except the left side of the upper, which bears Ted Nugent’s signature. If that’s too subtle, the other is cerakoted the colors of the American flag. If you want to build a well-functioning 6.5 Grendel gun that will also draw attention at the range, this is the one for you.

A Potted History of the 6.5 Grendel

product testing table

The 6.5 Grendel, which Military Times thinks might become a popular combat round in the next few years, was developed by Bill Alexander of Alexander Arms (the guy behind the .50 Beowulf) and Janne Pohjoispää as a way to help the AR-15 surpass 5.56m NATO cartridge performance for medium to long ranges (200-800 yards) with a STANAG magazine-length cartridge and without a redesign of the gun. 

In order to achieve this, the 6.5 Grendel uses a shorter, stubby cartridge and longer bullet to get reasonable muzzle velocity with as high a ballistic coefficient (BC) bullet as possible.

The 6.5 Grendel trademark was held by Alexander Arms until released in 2010 for SAAMI standardization in collaboration with Hornady.

Why choose the 6.5 Grendel?

  • More powder. Better ballistics. The shorter, larger diameter case allows the Grendel to pack more powder into the cartridge than the 5.56mm NATO while accommodating a long, high BC bullet, making for one of the most effective cartridges on the market today.
  • Better Long-Distance Performance. A typical 90-129 grain bullet will have a muzzle velocity anywhere from 2,500 ft/s to 2,900 ft/s muzzle velocity, but thanks to a higher BC than either the 5.56mm NATO or 7.62x51mm NATO rounds, the Grendel maintains more terminal energy at extended ranges — helping you hit a target at longer distances with more oomph.

What to look for in a 6.5 Grendel Upper

The Grendel is designed to deliver peak muzzle velocity with barrels 22-24" in length.
  • Purpose. When deciding on taking a dip in the Grendel pool, we recommend thinking through what you plan on doing with the rifle. What’s it’s intended purpose? A 12-inch upper would be great for home defense, but will be incredibly loud and struggle at extended ranges. The opposite is true for a 20-inch or 24-inch option, which will excel at long range but you’ll have a hell of a time getting around a corner with it.
  • Barrel Length. Depending on your intent, there are a few general guideline sfor barrel length. Hunting applications should target 22-14″ length to ensure maximum accuracy and shot placement. A 16-18″ set-up gives you a nice middle ground, handier silhouette and is a great option for folks who want a general use rifle that can get a lot done in a single package. Under 14″ and you’re getting into pistol territory, which will sacrifice almost 400fps relative to 22″ or longer options, but for those interested in a truck or hog gun, the Grendel can deliver.

Types of 6.5 Grendel Uppers

6.5 Grendel Uppers - Bench

You wouldn’t pack carry your entire collection of pistols with you in a rifle case and you’d get some funny looks from competitors if you pulled a 24-inch barreled AR from your bag to shoot cowboy action, so don’t bother with the wrong type of upper, either. Every 6.5 Grendel is designed for a specific type of shooting, so make sure you buy one that right one for your purpose.

  • Sub 14″ Uppers: While the 6.5 Grendel was engineered as an intermediate cartridge to occupy the performance sweet-spot between the 5.56×45mm NATO and the 7.62×51mm in a STANAG magazine-length cartridge, that doesn’t mean it can’t perform in a pistol format.  Most pistol-length 6.5 uppers will cost you 300-400fps but offer an unparalleled silhouette & mobility.
  • 14-16″ Uppers: For the RECCE rifle enthusiast in you, look for a mid-length upper, somewhere in the 14-16″ range. These will offer the most versatility, practicality, and offers serious terminal ballistics, well beyond the diminutive pistol options. They’re great for situations where you have multiple purposes for your rifle but aren’t keen on swapping uppers between sticks.
  • 22-24″ Uppers. Some say “long is strong”, and this is particularly true with the 6.5 Grendel. These uppers will be the most unwieldy, expensive, and considerably heavier than shorter barrels, but if you want to squeeze every MOA out of your rifle and are willing to invest in every opportunity to avoid a spoiled hunting trip, keep it 22″ or longer.

Pros and Cons

M-Lok Bipods - Caldwell Mounted on an AR

The 6.5 Grendel performs better for long-range applications than the 5.56mm NATO while maintaining intermediate cartridge size, which is the primary benefit to the round. That extra range and more kinetic energy delivered is what makes the 6.5 Grendel an excellent hunting and combat round.

Plus if you have an existing AR lower and want to get into a new cartridge, a complete 6.5 Grendel upper is an excellent way to do so because the round works will STANAG magazine-length ARs.

The downside to 6.5 Grendel is its cost. When ammo supplies are more normal, 6.5 is expensive when compared to other, similar bullets and especially when compared to the 5.56mm it replaces. 

6.5 Grendel Upper Pricing

Compared to some newer cartridges, like the .224 Valkyrie, uppers chambered in 6.5 Grendel are relatively affordable. Rest easy — there’s a 6.5 Grendel upper out there for you.

  • $500-$750. More budget-friendly uppers will start in the sub-$500 range and offer more conventional bolt & handguard materials — the great news is these uppers are often a great value and tend to perform as well as more expensive options. If you’re not itching for a specific brand or feature, you’ll find your goldilocks here. You’ll see brands like PSA and Anderson Manufacturing.
  • $750-$1,000. The upper-end of 6.5 Grendel uppers generally lands in the $750-$1,000 range and increases the frequency of nice-to-haves like improved an ambi charging handle, top-tier bolt/handguard, and bolt carrier group materials. If you’re planning on upgrading any of those components on your final build you might be able to go save a few bucks if you package them into one of these higher-end uppers. Brands you’ll see in this range are names like Ballistic Advantage, Aero Precision, and CMMG.


This relatively new round is an exciting combat and hunting round that, despite its price, is more than worth checking out.

Overall, the 6.5 Grendel offers capabilities to the AR platform that are in line with the design thinking that led most of NATO to the 7.62mm years ago, but with some great modern touches. Of course, when assembling your own AR all NFA rules apply, so just make sure you do your homework when it comes to pairing your new upper with an appropriate lower.

Further Reading

  1. Wikipedia, 6.5 Grendel 
  2. Military Times, Could 6.5 Grendel Become The Next Big Thing
  3. Alexander Arms, Company History
  4. Wikipedia, .50 Beowulf
  5. Rifle Shooter Magazine, 6.5 Grendel Evolution
  6., 6.5 Grendel Barrel Length Comparison

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