Best 6.5 Grendel Upper Receivers (2022) – An Overview

Best 6.5 Grendel Upper Receivers

The 6 .5 Grendel ammunition has gained popularity in recent years, especially among AR-15 platform upgrades and custom projects or a new rifle as many deem it a much more efficient replacement for the 5 .56 NATO. The 6 .5 Grendel round delivers the power of a 7.53 and the flat trajectory of a 5.56 round to improve the overall range of the rifle. This ammunition also provides a superior ballistic coefficient over longer distances and can help reduce recoil, especially when paired with a good muzzle brake.

Given the popularity, it is not a surprise to find many gun enthusiasts searching for the best 6 .5 Grendel upper receivers for their new rifle upgrade or custom projects. However, we also understand that searching for 6. 5 Grendel accessories is not the easiest task. And that is why we have searched through the internet to bring you a list of the best 6.5 Grendel upper receivers on the market.

Uppers Name Editor’s Comment Rating Get The Deal
Anderson Manufacturing 16” 6 .5 Grendel Upper

Most Recommended Option

1. Complete upper receiver with flash hider and BCG
2. 16-inch steel barrel with an optimum 1:8 twist rate
3. Top mounting railing system

10/10 SHOP NOW
ATI – AR-15 Complete Upper Receiver Black Keymod 6 .5 Grendel

Premium Option

1. Complete upper receiver with flash hider and BCG
2. 16-inch steel barrel with an optimum 1:8 twist rate
3. Top mounting railing system

9.5/10 SHOP NOW
American Spirit Arms – Side Charging Upper Receiver
1. Non-reciprocating upper receiver
2. Side charging handle helps you keep sight picture
3. Easy to install and adjust.
9.0/10 SHOP NOW
PSA 20” Rifle-Length 6 .5 Grendel 1:8 Stainless Steel 15” Lightweight M-Lok Upper Receiver 1. Affordable price tag
2. Anodized finish
3. Free float M-Lok railing
8.5/10 Currently unavailable
PSA 18” Rifle-Length 6 .5 Grendel 1:8 Stainless Steel 15” Lightweight M-Lok Upper Receiver 1. Machined from 416r stainless steel
2. Full-auto BCG profile
8.0/10 Currently unavailable
PSA 12” Carbine-Length 6 .5 Grendel 1:8 Nitride 10” Lightweight M-Lok Upper Receiver 1. Made in the USA
2. auto-profile bolt carrier group
3. M-Lok free-floating rail system
7.5/10 Currently unavailable

The Complete 6.5 Grendel Upper Receivers Buyer’s Guide

Before going into our list, there are a few key factors that you need to keep in mind while you shop for the best 6 .5 Grendel upper. This includes essential build quality and even special features that will make a difference in customizing your weapon.

Build Quality

A 6 .5 Grendel upper can be casted, forged, or even machined to exact specifications. Most owners experienced in the 6.5 Grendel weapon will tell you that forged is preferable over the other two options. Not only is forged considered as the superior standard for decades but forged upper receiver also tends to be more durable to stand up to years of vigorous use.


Those embracing an upgrade or building a weapon from scratch will need their upper receivers to be truly customizable according to their specs and personal taste. The best 6. 5 Grendel upper should allow you to replace or upgrade the barrel as well as accommodate additional optics that you like. Ideally, you also want a complete Grendel 6.5 upper that comes with a barrel and M-Lok Handguard to save you money and time. 


One important component of a 6. 5 Grendel upper is the handguard. Not only will a good handguard help you with customization, but it even gives you room to add or change accessories in the future. Ideally, you might want to consider a free-floating key mod handguard.

Forward Assist

This is yet another component that many might be tempted to dismiss. However, a good forward assist will come in handy, especially when your final rifle build is exposed to dust, dirt, and other outdoor debris. This can also help limit potential malfunctions when cycling around.

Barrel Length

The 6 .5 Grendel is an intermediate cartridge that yields long-range shooting accuracy that exceeds the .308 Winchester while outshining the 5.56 NATO. Fortunately, the 6 .5 Grendel round also produces consistent velocity with a barrel length from as short as 16 inch to as long as 24 inch.

Most people find that a 20 inch barrel works amazingly for the overall performance of the 6 .5 Grendel. Though this is not the only option available. A 20 inch Grendel 6 .5 barrel will have your bullet traveling pretty much the same distance as the 24 inch barrel with an arch drop a little more starting at 800 yards. Shorter barrels of around 14.5 to 16-inches will generate an even greater drop as the round approached 1,000 yards, limiting its effective range to approximately 800 yards.

The Types of 6.5 Grendel Uppers

The 6.5 Grendel uppers are designed to cater different purpose such as precision shooting and target shooting hence, you must be well-versed with the types of the best 6.5 Grendel uppers.

Sub 14″ Uppers

The 6.5 Grendel was invented as an intermediate cartridge to operate efficiently between the 5.56×45mm NATO and the 7.62×51mm in a STANAG magazine-length cartridge which includes in a pistol format. Most of the pistol length of 6.5 uppers will be pricy but great aesthetics, stability and durability.

14-16″ Uppers

As for RECCE rifle enthusiast, the ideal inch upper would be approximately 14-16″ range for maximum versatility and capable of excellent terminal ballistics. These 6.5 Grendel uppers are fantastic if you’re looking for something more versatile to cater other purposes as well.

22-24″ Uppers

This range of 6.5 Grendel uppers are on the pricier side and heavier than shorter barrels. However, if you want to optimize your MOA then you should invest in this 6.5 Grendel upper to ensure the best hunting rifle for your hunting applications.

The Best 6.5 Grendel Upper Reviews in 2022

Now that we’ve gone through some basics, let’s dive straight into the best 6.5 Grendel uppers available for purchase now.

1. American Spirit Arms – Side Charging Upper Receiver – The Best 6.5 Grendel Upper Overall


The American Spirt Arms 6 .5 Grendel upper receiver is one of the most innovative uppers on the market with the intention to relocate the charging handle of an AR-15 out of its usual position to the side to ensure better performance. His will also allow shooters to achieve a better shooting position while charging their rifles.

Additionally, you even have the ability to add on other accessories, such as scopes to enhance your rifle’s overall performance. The side charging 6 .5 Grendel upper is also made from anodized aluminum and weighs a mere 1.05 pounds featuring a charging handle on the side, rather than the rear.

The charging handle on the side-charged receiver does not reciprocate the action of the bolt, ensuring a much safer operation. The Grendel 6.5 upper is also compatible with most lower receivers and can even be quickly integrated with most rifles.

Other than that, the 6 5 Grendel upper offers plenty of room for customization, since it does not have a barrel and handguard. On top, you’ll find a Picatinny rail for you to mount adapters for optic scopes.

Overall, this 6 .5 Grendel upper features a new design with a side-charging handle to help you retain sight picture and offers fast failure clearing. It’s also much more accurate and easy to adjust, making it a great choice for overall use including hunting and self-defense.

You would like this upper receiver if:

  • You want a non-reciprocating upper receiver.
  • You prefer to have a side charging handle that helps you keep sight picture.
  • You want a 6 .5 Grendel upper that is easy to install and adjust.

You might not like this upper receiver if:

  • You want a forward assist
  • You don’t want to get a special bolt carrier with a notch cut to install the upper.


2. Anderson Manufacturing 16” 6 .5 Grendel Upper – The Runner-up 


This AR-15 6 .5 Grendel upper comes with a 16-inch barrel with a 1 :8 twist rate, making it a great accessory or add-on to a building project or new rifle. The steel barrel ensures better accuracy and precision right off the bat. So, if you want your rifle to become more of a sharpshooter almost immediately after installation, then you’d be hard-pressed to find another good 6.5 Grendel upper much like this one.

This complete 6.5 Grendel upper features a forged construction with an optic-ready flat top and A2 carbine handguard. As mentioned earlier, this 16 inches barrel has a 1:8 twist rate, which is the optimum rate for the 6 .5 Grendel round. It also has a .308 A2 flash hider.

The AR-15 6 .5 Grendel upper also comes with a charging handle and bolt carrier group, making it a complete package. It also has a forward assist to stop you from pushing in rounds when the cycling malfunctions.

Considering the parts included in the package and the price, this 6 .5 Grendel upper receiver certainly offers a good deal for the money. It is both well-fit and well-tuned for accurate shooting and hunting.

You would like this upper receiver if:

  • You want a complete Grendel 6.5 upper with flash hider and BCG included.
  • You need a 16-inch steel barrel with an optimum 1:8 twist rate.
  • You prefer 6 .5 Grendel uppers with a top mounting railing system for attaching accessories easily.
  • You want an upper with a relatively affordable price.

You might not like this upper receiver if:

  • You don’t want to use a conventional handguard.


3. ATI – AR-15 Complete Upper Receiver Black Keymod 6 .5 Grendel


The ATI 6 .5 Grendel uppers are ready-to-swap upgrades for your rifles. In fact, it is compatible with almost every AR-15 lower receiver, allowing you to entirely change the caliber of your rifle with a simple receiver exchange.

Designed and crafted from 7075 aluminum, this 6 .5 Grendel upper features an M4 contour barrel that’s surrounded by a 10-inch, free-float handguard. This free-floating handguard not only optimizes the accuracy of your rifle, but it even has keymod holes and a full-length, optics-ready, A3 flattop railing system to let you mount your favorite accessories and slings.

The 16 inches barrel installed also has an optimum 1 :8 twist rate and an all-oxide black finish that makes the steel barrel aesthetically pleasing. The bottom line is that the ATI upper receiver is a complete package that is good for hunting and long-range shooting.

You would like this upper receiver if:

  • You want the best 6 .5 Grendel upper that offers good value
  • You want a complete 6 .5 Grendel upper that includes a forward assist
  • You prefer a free float keymod handguard

You might not like this upper receiver if:

  • You don’t want something that may require fitting.


4. PSA 20” Rifle-Length 6 .5 Grendel 1:8 Stainless Steel 15” Lightweight M-Lok Upper Receiver

Made for the 20-inch rifle, this stainless steel 15-inch 6 .5 Grendel upper by Palmetto State Armory is forged from 7075 T6 aircraft-grade aluminum. Not only is this stronger than 6061 aluminum, but the cast also adds to the overall durability of the component. This process essentially compresses the aluminum alloy stock into the die shape to produce a more durable upper at a lower manufacturing price.

The PSA stainless steel 6 .5 Grendel upper is machined to MIL-SPECS in the United States, meaning that it meets every aspect of rigorous military specifications. It also features a hard coat anodized finish for superior corrosion and thermal resistance.

The 6 .5 Grendel upper also includes the bolt carrier group and charging handle in the package. The included free-floating M-Lok railing is also great if you’re thinking of adding various accessories. Many have even considered it to be superior to older railing systems like the Picatinny rail that only provides you with pre-set slots.


  • Affordable price tag to suit various budgets.
  • Anodized finish for enhanced durability.
  • Free float M-Lok railing for improved customizability.
  • Includes bolt carrier group and charging handle.


  • Only available in standard black color.
  • It may not suit left-handed shooters.

5. PSA 18” Rifle-Length 6 .5 Grendel 1:8 Stainless Steel 15” Lightweight M-Lok Upper Receiver

Like many other AR-15 6. 5 Grendel uppers offered by Palmetto State Armory, this stainless steel M-Lok upper is constructed from forged 7075-T6 A3 aircraft-grade aluminum and is machined with military-spec precision by a MIL-SPEC manufacturer. Similar to the model discussed above, this one also features an anodized hardcoat.

The main difference is that this 416r stainless steel 6 .5 Grendel upper is designed for the 18-inch rifle length with a hand guard that is large enough to mount your desired optics. It also comes with M-Lok free float rail by Magpul, a full auto-profile bolt carrier group, and a charging handle. The bolt is also nitride coated to help handle more firing while giving it a smooth look and feel.

However, there were some complaints of a tight fit when buyers tried to install this upper receiver. So, you might want to prepare to lubricate it in advance. You might also need to adjust the gas block to get it to cycle fully while breaking the 6 .5 Grendel upper in.


  • Machined from 416r stainless steel to be lightweight for easy maneuverability.
  • Comes with a full-auto BCG profile.
  • Made in the United States to MIL-SPEC.


  • A short railing for the intended rifle length.
  • Might be an overly tight fit during the initial installation.
  • Gas block may need adjusting.

6. PSA 12” Carbine-Length 6 .5 Grendel 1:8 Nitride 10” Lightweight M-Lok Upper Receiver

Next on our list is a 10-inch 6 .5 Grendel Upper that’s made for the 12-inch carbine-length AR. Constructed from forged 7075-T6 A3 aluminum alloy according to MIL-SPEC, this upper receiver features an anodized hard coat and includes charging handles as well as a full-auto profile bolt carrier group.

Like the other 6 .5 Grendel uppers by PSA reviewed above, this upper receiver has an M-Lok free float rail for you to swap out accessories quickly and position them wherever you want. The innovative Magpul rail system is obviously more versatile compared to any other rail systems like the Picatinny rail.


  • Made in the USA.
  • Comes with an auto-profile bolt carrier group
  • Features M-Lok free-floating rail system


  • The rail may be too short for some optics.


The bottom line is the best 6 .5 Grendel uppers are increasingly popular among gun enthusiasts who enjoy custom builds and upgrades. Thanks to the 6 .5 Grendel uppers’ versatility and overall build quality, they’ve made customizing projects all the more enjoyable. Finding the best 6 .5 Grendel upper for planned build includes factoring in the barrel length as well the rails. These days, many prefer to opt for the M-Lok free float rails that let you quickly swap out any accessories as needed.

A great thing about 6 .5 Grendel uppers is that some of them come as packages with other components included to spare you the time and effort needed to hunt down all the components together. Though there are certainly some who will swap out the bolt carrier group or barrel to match their own personal vision for the project, it is still nice to see these parts included in the initial purchase.

Frequently Asked Questions (FAQ)

Is the 6.5 Grendel ammunition better than the .308?

Yes, the 6.5 Grendel ammunition might be better if you tend to spend long days at the range as it will save you a little bit of money over the long-term life of the gun.

What are the benefits of the M-Lok railing system?

M-Lok stands for “Modular Lock” which was invented by Magpul Industries that is a special type of railing interface system that lets you attach accessories directly. It also provides a slimmer, lighter, and smoother handguard with more available space for you to mount accessories. This ultimately leads to greater customization compared to competitive railing systems which offer only specific slots.

Is there a difference between a 6.5 Grendel and a 6.5 Creedmoor?

At first glance, both the 6.5 Grendel and 6.5 Creedmoor have the same .264” bullet diameter. However, the 6.5 Grendel is a little lighter than somewhat smaller than the 6.5 Creedmoor, which means that it uses a smaller case with less gun powder. The 6.5 cases will produce 2,350 FPS while the Creedmoor produces approximately 2,850 FPS. This also means that the Creedmoor rifle will need a longer barrel and a lower magazine capacity.

Is it possible to install a Grendel upper onto a 5.56 or .223 lower receiver?

If your current AR-15 is chambered in 5.56 NATO or uses a standard lower receiver for another cartridge, then you can conceivably install a 6.5 Grendel upper onto it. However, this process may be a little complicated and it’s not ideal for a novice do-it-yourself gunsmith to embark on.

Is 1:8 or 1:9 twist ratio better?

Many owners prefer a 1:8 twist rate as it helps to stabilize the heavier rounds of 130 to 140-grains without over-stabilizing the lighter 90-grain loads. This means that you get to enjoy long-range shooting at the range and still have fun plinking. The 1:9 twist rate, on the other hand, will do well and may even slightly improve accuracy if you’re shooting lighter loads exclusively.


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