The Aero M4E1 Grendel Hunter is a 6.5 Grendel rifle made from an Aero Precision M4E1 lower and a 22-inch Grendel Hunter upper receiver. Aero is widely known for making quality AR rifles, but it's the specific caliber that makes this review a special one for me. 

You may have seen a popular meme about some of the more popular 6.5 cartridges that makes some satirical characterizations about the owners of these cartridges. The 6.5 Grendel character is represented by a kooky and eccentric-looking fellow you might not want to approach in the truck stop parking lot. I always laughed a bit at this meme, but today I find myself with that character’s same wide-eyed stare.
 

Aero Precision M4E1 Grendel Hunter rifle
After shooting the M4E1 Grendel Hunter, I can relate to the 6.5 Grendel character's reaction.
 

Table of Contents

Overview
The Specs
Ammunition
On the Range
Pros & Cons
Conclusion

Overview


The Grendel allows you to shoot 6.5 (.264) caliber bullets from a small-frame AR-15-type rifle, which can vastly change the utility of your AR-15. I have heard of people using the Grendel for hunting animals as big as Rocky Mountain elk, and having used bullets of the same size and velocity, I can see why. 
 

Aero Precision M4E1 Grendel Hunter rifle
The 6.5 Grendel packs enough power to stop big game like Rocky Mountain elk. (Photo: Jeff Wood/Guns.com)


The only difference I’ve noticed – apart from the 6.5 Grendel barrel – between this and other AR-15 rifles is the use of a different magazine. The Grendel magazines use a different follower, and I had a few lying around from my 6mm ARC project, so they got put to good use.

 

The Specs


The upper features a 22-inch barrel with an 1:8 twist and a 5/8x24 TPI threaded muzzle, of course chambered in 6.5 Grendel. The Grendel is a bit of an oddity in that it uses a cartridge case that uses a bolt face between the common .223 Remington and the .308 Winchester. There are only a few common cartridges that use this size case, such as the .224 Valkyrie and the 6mm ARC.

The barrel is a fluted stainless one with a low-profile gas block installed, and since it was threaded, I fully intended to install a suppressor to see how the rifle performed as a host.
 

Aero Precision M4E1 Grendel Hunter rifle
The upper features a 22-inch barrel with an 1:8 twist and a 5/8x24 TPI threaded muzzle, of course chambered in 6.5 Grendel. (Photo: Jeff Wood/Guns.com)

 

Aero Precision M4E1 Grendel Hunter rifle
Outfitted with my US Optics FDN17X, M-LOK Harris bipod mount, and Yankee Hill Machine Nitro N20 suppressor, the rifle is ready to hit the range. (Photo: Jeff Wood/Guns.com)


After getting the rifle home, I set it on my bench and started looking for suitable accessories. First and foremost, it needed a good scope. For that, I decided on my US Optics FDN17X, since it seemed like a good match to the anticipated shooting for the Grendel. Then I installed an M-LOK Harris bipod mount on the handguard and grabbed my Yankee Hill Machine Nitro N20 suppressor.
 

Ammunition


6.5 Grendel ammunition isn’t as common as most, so I knew going in I would need to improvise. I had a bunch of 6.5 Grendel brass already – yes, I am unashamedly one of those range creeps that is always digging through brass piles. But I haven’t bought brass in years, so I’ll happily take the troll title.
 

Aero Precision M4E1 Grendel Hunter rifle
I loaded some PRVI 120-grain BTHP bullets with Hodgdon Benchmark in Hornady brass for this test. (Photo: Jeff Wood/Guns.com)


I have a broad selection of .264 bullets, but it seems that Grendel loads are frequently in the 100-120 grain category. So I decided I would load up some PRVI 120-grain BTHP bullets with some Hodgdon Benchmark in Hornady brass. While I claim no expertise in the dark art of handloading, I managed to get them together without any explosions or injury. So with the outfitted rifle and my freshly loaded ammo, I headed into the hills to see how the rifle shot.
 

On the Range


With a fresh target hung at 100 yards, I laid behind the rifle to get it zeroed. I had already bore-sighted it before I left the house, so it was ready to put on paper. After the first few shots, I made some adjustments to the scope and fired a group to see how it patterned.
 

Aero Precision M4E1 Grendel Hunter rifle
A starting point of one MOA for five shots isn't bad. (Photo: Jeff Wood/Guns.com)


My grouping wasn’t terrible – a five-shot average of one MOA is somewhere to start, at least. It’s certainly possible the rifle didn’t care for my handloads, and had I been shooting some Hornady Match, it might have shot under a half-inch. I shot several boxes of ammunition, and to be honest, I can see why so many people like this little cartridge. The recoil is mild, for starters, and I can’t imagine it would be much worse even shooting 140-grain bullets.

It was even better when I added my suppressor. I was able to stretch the rifle out to about 500 yards, where I found it still quite easy to hit targets the size of a deer’s vitals.
 

Pros & Cons

Everybody has their preferences, and I surely have mine, so I’ll tell you what I would do with this rifle if I had a magic wand. First, I think I’d cut the barrel down a bit, as it seems cumbersomely long to me. The long barrel also makes it front-heavy, which if you’re shooting from a bipod isn’t a big deal, but it can be for an offhand shooter.

Second, the Grendel is one of those cartridges I wouldn’t expect to be blasting one rapidly after another, so the 10-round magazine is more than enough for my purposes, but you may want more if you are a high-volume kind of shooter.

I do like the construction of the rifle, but the lightweight handguard doesn’t have anything more than what you want. The quality coatings look good, and everything fits together great. The bolt carrier appears to be nitrided for durability and smooth operation, while the raw steel surface of the barrel gives you that 2006 vibe.
 

Aero Precision M4E1 Grendel Hunter rifle
I prefer to shoot my deer one at a time, but it’s still reassuring to know the Grendel Hunter has a magazine full of backup shots waiting. (Photo: Jeff Wood/Guns.com)

 

Conclusion


The Grendel Hunter part of this rifle makes a whole lot of sense to me. You get a handy little lightweight rifle, but at the same time you get a whole magazine full of 6.5mm bullets to pummel whatever it is you’re after. I prefer to shoot my deer one at a time, but it’s always reassuring to know you have a stack of backup shots waiting for you. 

Furthermore, I think this would be an excellent hog gun, where you may need a whole bunch of hard-hitting shots close together. Loaded with 140-grain bullets, I could easily see using this rifle for big Western game like elk and bighorns. We’ve killed elk using the same bullets and velocities tested in this rifle.

There is obviously no shortage of good choices in today’s firearms markets, but this rifle is a great option for someone who needs this kind of firepower and weight. The kooky eyes and hairdo are entirely optional (I wouldn’t recommend the look).

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