6.5 Grendel ammunition has become increasingly popular in recent years, especially in AR-15 upgrades and custom builds. It’s seemingly taken over a far more efficient replacement for the 5.56. It gives you the basic power of a 7.62 round married to the flat trajectory of a 5.56 round. Not only does this improve the overall range of the rifle, but it also helps with providing a superior ballistic coefficient over long distances and to reduce recoil, especially with a good muzzle brake.
Given this level of popularity, there are a lot of great uppers to consider for your 6.5 Grendel upgrade or custom build. With that in mind, there are a few things you will want to factor in when shopping for the best 6.5 Grendel Upper for your next AR-15 project. This includes things like weight, material, build quality, the handguard, and other special features. After spending hours researching the market, we gathered selection of amazing options that offer great quality for a reasonable price.
Best Overall: PSA 20″ Rifle-Length 6.5 Grendel 1:8 Stainless Steel 15″ Lightweight M-Lok Upper
This Palmetto State Armory 6.5 Grendel Upper is meant for a 20-inch rifle length AR. It’s forged from aircraft-grade aluminum for long-term durability and exactingly machined to MIL-SPECS in the United States. It has a 15-inch M-Lok rail with plenty of room for adding custom optics and accessories. Like most PSA 6.5 Grendel uppers the BCG and CH are included in the original purchase. This particular bolt carrier group comes with a full-auto profile. If you plan on replacing the bolt check out guide on 6.5 Grendel bolts.
Best Lightweight 6.5 Grendel Upper: PSA 18″ Rifle-Length 6.5 Grendel 1/8 Stainless Steel 15″ Lightweight M-Lok Upper
This PSA 6.5 Grendel Upper is made in the USA and from forged from aircraft grade 7075-T6 A3 aluminum alloy to make it exceptionally durable. It’s machined to MIL-SPECS and designed to be lightweight with an anodized hard coat. It’s meant to be installed on an 18-inch rifle length. A full-auto profile bolt carrier group and charging handle are included as standard. The M-Lok free float rail offers plenty of room for custom optics and other accessories.
Best Carbine-Length Upper: PSA 12″ Carbine-Length 6.5 Grendel 1/8 Nitride 10″ Lightweight M-Lok Upper
Meant for a 12-inch carbine length this 6.5 Grendel upper is forged 7075-T6 A3 aircraft-grade aluminum alloy and machined to MIL-SPECS with an anodized hard coat. The charging handles and a full auto-profile bolt carrier group are included in this model package. It also has an M-Lock free float rail to let you quickly swap or customize optics and other accessories.
6.5 Grendel Upper Buyer’s Guide
There are a few key factors to consider when shopping for the best 6.5 Grendel Upper for your build or upgrade. This goes beyond essential build quality as well as special features that let you truly customize your weapon as you see fit.
A 6.5 Grendel upper receiver might be cast, forged, or machined to exact specifications. Most people who are experienced in 6.5 Grendel custom builds will tell you that a forged unit is preferable and has been considered the superior standard for several decades. The reasoning behind this is that a forged upper tends to be more durable, which means it can stand up to years of vigorous use.
The ability to truly customize your 6.5 Grendel upper to your specs and personal taste is a priority for most people embracing an upgrade or a custom build. The best 6.5 Grendel upper should allow you to easily replace or upgrade the barrel as well as accommodate additional optics. Ideally, you want a complete upper receiver that includes a barrel as well as a M-Lok handguard. This will ultimately save you money, and time as you don’t have to spend hours shopping online for compatible aftermarket accessories.
As simple as it might seem, a quality handguard is a very important component of a 6.5 Grendel upper. Not only does it help with customization, but a good handguard ensures that you can use you have room to add or change accessories throughout in the future. Ideally, you might want to give preference to a free-floating key mod handguard.
A Forward Assist
A forward assist is another one of those simple things that you might be tempted to dismiss. Though a quality one will come in handy when your final rifle build is exposed to dust, dirt, and other outdoor debris. It can also help limit potential malfunctions when cycling around.
Choosing A Barrel Length
The intermediate cartridge is one of the more appealing things about the 6.5 Grendel. It yields long-range accuracy which can exceed the .308 Winchester while outshining the 5.56 NATO. Fortunately, the 6.5 Grendel is a forgiving round that produces consistent velocity with a barrel length from as short as 16-inches to as long as 24-inches.
Most people find the 20-inch barrel is a great all-rounder for overall performance. Though it’s certainly not the only option worth considering. To take a closer look at the numbers. With a 20-inch Grendel 6.5 barrel, the bullet will travel pretty much the same distance as a 24-inch barrel. Though the arch will drop a little bit more starting at 800 yards to the point where it will drop around 8-inches comparatively. When we take it out to 1,000 yards, you see an additional 21-inch drop and a significant decrease in velocity of around 30 FPS. When we look at shorter barrels around 14.5 to 16-inches there’s even greater drop as the round approaches 1,000 yards, which limits the reasonable effective range to 800-yards.
6.5 Grendel Upper Reviews
PSA 20″ Rifle-Length 6.5 Grendel 1:8 Stainless Steel 15″ Lightweight M-Lok Upper
This 15-inch 6.5 Grendel upper by Palmetto State Armory is meant for a 20-inch rifle length. It’s forged, from 7075 T6 aircraft-grade aluminum, which is stronger than 6061 aluminum. Being cast also adds to the overall durability. The process essentially compresses the aluminum alloy stock into the die shape. Not only does this make for a more durable upper, but it also reduces the manufacturing price, which is passed on to you. The overall length is 26.5 inch.
It’s machined to MIL-SPECS in the United States. This means that every aspect meets rigorous military specifications. It also has an anodized hard coat for superior corrosion and thermal resistance, as well as increased surface hardness.
This particular model includes the bolt carrier group and the charging handle in the purchase. It comes with an M-Lok rail which is great if you are thinking about adding various accessories. This type of free-floating rail system by Magpul is considered by most to be superior to older rail systems like Picatinny which only provides you with pre-set slots.
- A very friendly price tag
- An Anodized finish
- Free-float M-Lok rail for customizing accessories
- Includes bolt carrier group
- Includes charging handle
- It’s only available in standard black
- The charging handle is only right-handed
PSA 18″ Rifle-Length 6.5 Grendel 1:8 Stainless Steel 15″ Lightweight M-Lok Upper
Like many of the 6.5 Grendel uppers offered by Palmetto State Armory, this model is made in the USA from forged 7075-T6 A3 aircraft-grade aluminum. It’s then machined with Military spec precision by a MIL-Spec manufacturer. It also has an anodized hard coat anodized.
This 15-inch upper is meant for 18-inch rifle length, the hand guard is easily large enough to mount your desired optics. The machining arguably has an attractive look. The M-Lok Rail by Magpul, let’s you adjust or swap out optics and other accessories with ease.
The bolt carrier group has a full auto-profile and is included in this package, along with the charging handle. The bolt is nitride coated which helps it handle more firings while also giving it a smooth look and feel. The overall length is 26.5 inch.
- Machined to be lightweight and maneuverable
- Full auto BCG profile
- Made in the United States to MIL-SPECS
- Arguably short rail for the intended rifle length
PSA 18″ Rifle-Length 6.5 Grendel 1:8 Stainless Steel 15″ Lightweight M-Lok Upper
This Grendel upper is meant for an 18-inch rifle length build. Like many of the 6.5 Grendel Uppers offered by Palmetto State Armory, it is forged in the United States from 7075-T6 A3 aluminum. The upper is machined to MIL-SPECS and hard coat anodized. This level of build quality helps to maximize the long-term durability.
The bolt carrier group included in this upper has a full-auto profile. The charging handle is also included. The 15-inch handguard comes with an M-Lok free-floating rail from Magpul. It lets you easily change out accessories or customize your build without having to worry about slot spacing that you have to deal with on some other rail systems. The overall length is 24.5 inch and therefore slightly shorter than the other 15 inch upper on our list.
Some people complain about a tight fit during the install with this upper. Be prepared to lubricate it in advance. You might also need to adjust the gas block to get it to cycle fully while breaking it in.
- High material build quality
- Made in the United States
- Bolt carrier group has a full-auto profile
- Overly tight fit during the initial install
- The gas block may need adjusting
PSA 12″ Carbine-Length 6.5 Grendel 1:8 Nitride 10″ Lightweight M-Lok Upper
This 10.5-inch 6.5 Grendel Upper is meant for a 12-inch Carbine-length AR. It’s made from Forged 7075-T6 A3 aluminum alloy in the United States. The upper receiver is precisely machined to MIL-SPECS with an anodized hard coat. This particular model includes the charging handles as well as a bolt carrier group with a full-auto profile.
Like all of the 6.5 Grendel uppers offered by Palmetto State Armory, this model has an M-Lok rail. It allows you to swap out accessories quickly and position them where you want them. This innovative rail system by Magpul is far more versatile than other rail systems like Picatinny, where you only have a few preset slots on the rail.
- Made in the USA
- Full auto-profile BCG
- M-Lok free-floating rail system
- May be too short for some optics
Frequently Asked Questions
Is 6.5 Grendel Ammunition A Better Choice Than .308?
At first glance 6.5 Grendel rounds and .308 are very similar. Though 6.5 tends to cost less per round. Especially if you are buying in bulk. So, if you like long days at the range, the 6.5 Grendel will save you a little bit of money over the long-term life of the gun.
What Are The Benefits Of An M-Lok Rail?
M-Lok stands for “Modular Lock” and was invented by Magpul Industries. This is a special type of rail interface system that lets you directly attach accessories. It provides you with a slimmer, lighter, and smoother handguard and more available space to mount accessories for greater customization than competitive rail systems which only offer specific slots.
Do I Need A Forward Assist?
When it comes to AR-platform rifles, pistols & carbine a forward assist isn’t technically necessary. Though some would argue that it does come in handy if you are planning on taking your AR-platform rifle out in the field where dirt and random debris could potentially foul the bolt. Then the forward assist can be used to force the round into the chamber and the bolt into the firing position.
Is There A Difference Between A 6.5 Grendel And A 6.5 Creedmoor?
At first glance, both the 6.5 Grendel and the 6.5 Creedmoor use the same .264″ bullet diameter. However, the 6.5 Grendel is a little lighter and a little bit smaller than the 6.5 Creedmoor. This also means that it uses a smaller case with less powder. If you loaded each type with the same 129-grain bullet, you’d find that the Grendel case will produce 2,350 FPS and the Creedmoor will produce at 2,850 FPS. This also translates into a Creedmoor rifle needing a longer barrel as well as a lower magazine capacity. Speaking of magazines, we also covered the best 6.5 Grendel magazine options.
Is It Possible To Install A Grendel Upper Onto A 5.56 Or A .223 Lower Receiver?
Assuming that you currently have an AR-15 that’s chambered in 5.56 or that uses a standard lower receiver for another cartridge, you can conceivably install a 6.5 Grendel upper onto it. Though this is a little bit more complicated of an install, and not one that’s ideal for a novice do-it-yourself gunsmith.
Which Is Better A 1:8 or 1:9 Twist Ratio?
Part of selecting the best 6.5 Grendel Upper includes choosing the right barrel. To that point, a lot of packages include barrels in the model purchase. Though you might still want to swap out as you see fit for a custom build or upgrade. A lot of Grendel owners prefer a 1:8 twist rate as it helps to stabilize the heavier rounds of 130 to 140-grains without over-stabilizing 90-grain loads or less. This means you can enjoy long-distance shooting at the range, yet still have fun plinking. With a 1:9 twist rate will suffice and may improve accuracy slightly if you’re shooting exclusively lighter loads.
What Is BCG & CH?
The acronym BCG in a product title indicates that the bolt carrier group is included in the purchase. Many BCG has a full-auto profile, though this isn’t always true. Some custom builds will plan on swapping out the bolt carrier group in the design. Though it’s still nice to have one included. CH refers to the charging handle and is pretty much standard in most 6.5 Grendel upper packages.
6.5 Grendel uppers are increasingly popular with a lot of custom builds and upgrades. This is thanks to their versatility and overall build quality. Finding the best 6.5 Grendel upper for your planned build includes factoring in the barrel length as well as the rails. These days a lot of people prefer M-Lok free float rails which lets you quickly swap out optics and other accessories as needed.
A lot of 6.5 Grendel upper receivers come as packages with other components included. This spares you having 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 vision for the build. Still, it’s nice to see them included in the initial purchase.
Featured image by RobinHoodie5