Best 6.5 Grendel Uppers – Fully Reviewed & Rated

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. So let’s begin.

Best 6.5 Grendel Uppers Comparison Chart


American Spirit Arms - Side Charging Upper Receiver

  • 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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Anderson Manufacturing 16" 6.5 Grendel Upper

  • Complete Upper Receiver With Barrel and Handguard
  • Includes a .308 A2 Flash Hider and Complete BCG
  • Offers Best Value for Money
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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 such a good amount of money. Upper receivers are not cheap and we all know that. Right? So let's get on with this:

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.

Personalization: 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

Forged: 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.

Customizable: A good upper receiver must be customizable. It should allow you to replace the 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 malfunctions while cycling a round. However, using it, or not, is your own discretion.

Quick Take - The Best 6.5 Grendel Uppers

Review of the Best 6.5 Grendel Uppers

Based upon 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.


  • 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)

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.

Bottom Line

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

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.

Bottom Line

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.


  • 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 which 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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