Best 6.5 Grendel Uppers – Fully Reviewed & Rated

| Last Updated:
October 2, 2023

Introduced not very long ago, the revolutionary 6.5 caliber has taken the firearm community by storm. The cartridge was specifically designed for the AR-15 as a more efficient replacement to the 5.56.

That said, in order to use a 6.5 Grendel round, you need to change your upper, due to the difference in size of the rounds.

Here we’ll discuss the benefits of upgrading to a 6.5 Grendel upper, as well as the features an ideal one must have. We will also review the best 6.5 Grendel uppers on the market to help you make a purchase. Let’s begin!

Comparison of the Best 6.5 Grendel Uppers

  • Assembled Aluminum Made Side Charging Upper Receiver
  • Works With Multiple Calibers and Lower Receivers
  • Charging Handle Does not Reciprocate While Firing
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What Are The Benefits of Upgrading to a 6.5 Grendel Upper?

Before upgrading your upper to the 6.5 Grendel, you must understand its benefits. That’s because if there are no benefits, there’s no point in spending your money. Upper receivers are not cheap and we all know that.

A Better Rifle

The 6.5 Grendel caliber was invented to combine the power of the 7.62 and the Ballistic Coefficient (flat trajectory) of the 5.56 rounds. Using these upgraded rounds improves the range of your rifle, reduces recoil, and offers a flat trajectory over long distances.

Shooting using a 6.5 grendel upper (Source)

Saving Money

There’s no point in buying a new rifle to fire the 6.5 caliber. Just replacing your upper receiver with a new one will solve the problem. Plus, it will save you at least a couple hundred dollars, if not more.

Avoid Hassle 

Buying a new rifle will mandate you to perform a lot of paperwork and spend more time choosing the rifle. Simply upgrading the upper will protect you from all these unnecessary activities.


Maybe you have upgraded your stock or grip recently or are quite used to them so you don’t want to use a new one. Changing your upper will leave you with your existing lower receiver, thus not disturbing your personalization.

Weight and Economics

The 6.5 Grendel is a lighter round compared to the .308 and is also less expensive. If you like to burn through a lot of ammo, the 6.5 Grendel will be a better choice.

6.5 grendel vs .308 (Source)

Features of Our Top Picks


An upper receiver can either be forged, machined, or cast. The best among these is a forged upper receiver, which has been a standard for decades. That’s because forged metal retains more strength compared to any other form. Using a forged receiver will ensure that it stays long and strong. All uppers reviewed here are forged.


A good upper receiver must be customizable. It should allow you to replace the grendel barrel and offer room to mount desirable optics. In most cases, a complete upper receiver with a barrel and a handguard is the best option, as it saves money, and prevents you from the hassle of finding and buying compatible aftermarket accessories.

Good Handguard 

An upper with a good handguard ensures that you can use your desired accessories and have room for customization. It is always good to go for a free-floating keymod type handguard. Four out of five of our picks feature good handguards.

Forward Assist

It may not always seem necessary to have one, but a forward assist is still a good feature to have on your upper receiver. It comes in very handy when your rifle is exposed to dirt, or when it malfunctions while cycling a round. However, using it or not is up to your own discretion.

Review of the Best 6.5 Grendel Uppers

Based on the aforementioned features and qualities, we have selected and reviewed the best 6.5 Grendel uppers on the market. Each of these receivers is metal forged and offers enough customizability to let you use aftermarket accessories.

Best Overall:
 American Spirit Arms - Side Charging Upper Receiver


  • Non-reciprocating
  • Keeps sight picture
  • Side-charging handle
  • Easy to install and adjust
  • Offers room for customization


  • Lacks forward assist
  • Requires a special bolt carrier (notch cut)

What Recent Buyers Report 

New buyers say that this upper receiver was easy to install and allowed them the ability to customize it as they saw fit. They said the Picatinny rail provided them a good amount of space for them to install their favorite accessories. One user said that it didn’t take him long to install this and was also impressed with the overall quality.

Why it Stands Out to Us 

This is one of the most innovative upper receivers on the market. The intent of this upper is to relocate the charging handle of an AR-15 out of its usual position and be moved to the side to ensure a better performance. This will also allow shooters a better shooting position while charging their rifles. On top of that, you have the ability to add on some accessories like scopes so you can enhance your rifle’s performance beyond installing this. 

This 6.5 Grendel upper receiver from American Spirit Arms has been made from anodized aluminum and weighs only 1.05 pounds. The receiver features a charging handle on the side, rather than the rear, which will allow you to charge the weapon without changing your shooting position.

Additionally, the charging handle on this side-charged receiver does not reciprocate with the action of the bolt, providing a much safer operation. The upper is compatible with most lower receivers and can be integrated quickly and easily with most rifles.

This upper also offers room for customization, since it doesn’t have a barrel and handguard. The top of the receiver has a Picatinny rail, which lets you mount adapters for optic scopes.

Who Will Use This Most 

If you are planning on making some upgrades to your AR-15, you may want to consider the idea of looking at this upper a bit closely. This will be the kind of upper that will keep you focused on the target if and when your original charging handle tends to malfunction. A side charging handle isn’t such a bad thing to have after all, right?

Bottom Line

The American Spirit Arms Side Charging upper receiver is innovative and one of those hard to find accessories that you can use for a 65 Grendel rifle. Once you install this bad boy, you better believe that your rifle’s performance will be much better than before. Let’s not forget, you can still make it even better with a few additional add-ons to the rail as well. 

This 6.5 Grendel upper features a new design with a side-charging handle. This lets you retain the sight picture and offers fast failure clearing. It is also accurate and easy to adjust. Good for overall use which includes hunting and self-defense.


  • Complete upper receiver
  • 16” barrel with 1:8 twist rate
  • Flash hider and BCG included
  • Low price compared to counterparts
  • Top mounting rail for optics and accessories


  • Conventional handguard

What Recent Buyers Report 

About half of the new buyers were using this for the purpose of adding on to their building project. They said that the installation took just less than a half-hour. Others who were using it as a stand-alone upgrade for the purpose of boosting accuracy and opening up the doors to the opportunity of adding on more accessories using the top rail. Either way, they were able to get the achieved result they wanted. 

Why it Stands Out to Us 

This upper receiver contains a 16-inch barrel that has a barrel twist of 1:8. So, a good part of the work is done for you if you are looking to use it as an accessory or add-on to a building project. The barrel will allow for better accuracy and precision right off the bat. If you want your rifle to become more of a sharpshooter almost immediately after install, then you’d be hard-pressed to find an upper like this anywhere else. 

A complete upper receiver from Anderson Manufacturing. This one features a forged construction with optic-ready flat top and A2 carbine handguard. The receiver has a 16-inch barrel with a 1:8 twist rate, which is optimum for the 6.5 Grendel round. Plus, it also features a .308 A2 flash hider.

The upper also includes the charging handle and bolt carrier group, making it a complete package. The receiver also has forward assist, so you can’t push in rounds when the cycling malfunctions. Considering all the parts included in the package and the price, this upper receiver is a good deal for the money.

Who Will Use This Most 

Since this has a barrel included, this will definitely be a great upper for those looking to save a bit of money rather than spend it on extra parts. You have a barrel and a rail (among other accessories) included within the upper receiver itself. It’s a perfect fit for almost any rifle that is chambered to fire 6.5 Grendel rounds. For an upper receiver that will be well-fit and well-tuned for accurate shooting, this one should be a no-brainer decision.

Bottom Line

The Anderson Manufacturing 6.5 Grendel Upper is something you’ll want to consider for the purpose of building your rifle from scratch or if you want a simple upgrade that will up your accuracy and tighten your shooting groups. It’s built tough and won’t weigh your rifle down in the slightest. 

This 6.5 Grendel Upper from Anderson Arms is a complete package, at an optimum price. Except for the conventional handguard, this upper is complete, useful, and customizable in every other aspect.

3. ATI- AR-15 Complete Upper Receiver Black Keymod 6.5 Grendel


  • Good value
  • Complete upper
  • Includes forward assist
  • Aesthetically pleasing finish
  • Free-floating keymod handguard


  • Requires fitting

This 6.5 Grendel upper from ATI is a ready-to-swap upgrade for your rifle. This upper is compatible with almost every AR-15 lower receiver, allowing you to entirely change the caliber of your rifle by a simple receiver swap.

The upper has been designed from 7075 aluminum and features an M4 contour barrel surrounded by a 10-inch, free-float handguard. The free-floating handguard, not only optimizes the accuracy of your rifle, but it also has keymod holes and a full-length, optics-ready, A3 flattop rail to let you mount accessories and slings.

The 16-inch barrel installed in the receiver has an optimum 1:8 twist rate, plus the all-oxide black finish makes the barrel aesthetically pleasing.

Bottom Line

The ATI upper receiver is a complete package with optimum parts. The free-floating keymod handguard is a useful addition to its design. The upper is in general good for hunting and long range shooting, as well as self-defense. It is easy to swap, however, might require some fitting and adjustments in rare cases.


The 6.5 Grendel combines the power of the 7.62 caliber and the ballistic coefficient of the 5.56. It is a more efficient, lightweight, and low recoil caliber that improves your accuracy.

Using a 6.5 Grendel upper prevents you from buying a comparatively expensive new rifle. Plus, a good 6.5 upper, offers customizability. You must always consider the handguard, forward assist, ejection port, and the BCG before choosing a 6.5 Grendel for your AR-15.  

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