Alexander Arms 6.5mm Grendel AR-15 Rifle

   
   

by Jeff Quinn

photography by Jeff Quinn

January 13th, 2005

 

 

 

 
 

It all started almost two years ago at the 2003 SHOT Show in Orlando, Florida. I was talking with Bill Alexander of Alexander Arms about the great success of his .50 Beowulf rifle when he reached into his pocket and pulled out a very interesting little cartridge, looking much like a 6mm PPC. It was a new cartridge that Bill was working on that used a 6.5mm bullet in what was basically a necked up 6mm PPC case.  The PPC cartridge case is a dandy little design whose lineage goes back to the .220 Russian cartridge. The PPC case has proven itself admirably in benchrest competition, both in the 6mm and .22 caliber chamberings. What piqued my interest was that Bill had necked the thing up to take the beautifully efficient 6.5mm bullets that are available to shooters, and even more so that he was building an AR-15 rifle to fire the little cartridges.  As I stated, but it bears repeating, this was almost two years ago.

After making a couple of modifications to the PPC case to increase internal capacity, enhance accuracy, and increase strength to function better in AR-15 type rifles, the design was to become the 6.5mm Grendel cartridge. After first inspecting the little cartridge, it has been on my mind every since.

The AR-15 design has been with us now for over four decades, and has evolved into one of the most accurate and reliable rifle designs built today.  Attempts at increasing its power has mostly been directed at increasing the weight of the .223 bullet, and to improving the earlier AR-10 rifle. While the .223 certainly has its place as a  combat rifle, and I dearly love a good AR-10, the idea of a more effective cartridge on the handier AR-15 rifle greatly intrigues me. The 6.5 Grendel appeared to be an excellent solution to the need for increasing the power and effective range of the AR-15, and I was anxious to try one out. Again as I stated above, but it bears repeating, this was almost two years ago!

Bill Alexander, being somewhat of a Sadist, has kept me waiting for a production gun for all of this time. To his credit however, he did not want to go into production with this rifle until everything was just right. In the meantime, he has kept in touch with me detailing the progress of the new rifle, as a form of slow torture. Finally, a few weeks ago, I received the news that the rifle had arrived, along with a supply of factory ammunition and reloading dies.

Alexanders goal in developing the Grendel was as a long range target cartridge, and as a hunting rifle, particularly for deer-sized game. It also is a very good choice for a law enforcement tactical rifle. As a target rifle cartridge, the 6.5 Grendel has a lot to offer. 6.5mm bullets are available with long, sleek profiles, resulting in very high ballistic coefficients that contribute to a greater retained velocity and wind resistance.  Out past 1100 yards, the 6.5 Grendel is still supersonic. It is also flatter shooting than the .308 Winchester (7.62mm NATO), and much flatter shooting than the .223 Remington  (5.56mm NATO) cartridge. The Grendel also has roughly half the recoil of the .308 Winchester.  Getting a cartridge to push the beautifully streamlined 6.5 bullets to optimum velocities, while working within the size and operating pressure limits of the AR-15 system  was the goal of Alexander in designing the Grendel. For long range wind-bucking ability, and a relatively high retained velocity, the Grendel has succeeded admirably. The power of the 6.5 Grendel is much closer to the .308 than it is to the .223. In fact, at long range, some of the Grendel 6.5 loads have more retained energy than does the .308 cartridge, due to the efficiency of the cartridge and the very low drag ballistic properties of the bullets.  All this in the standard size AR-15 rifle.

As the question is certain to come up, this is as good a time as any to address the comparison between the 6.5 Grendel and another recent cartridge developed for the AR-15: the 6.8 Remington.  A quick look would suggest two very similar cartridges. However, the two were developed for different purposes. While the Grendel was designed for long range target work and hunting, the Remington was developed for anti-personnel use at ranges out to about 400 yards. The Grendel case has  a bit more powder capacity than does the 6.8 Remington, which matters little for a medium range combat cartridge. For long range work, the Grendels case design has a decided advantage over the Remington  when using long bullets of a high ballistic coefficient design, because both cartridges are limited in length by the size of the AR-15 magazine. In the accompanying photo, it is illustrated in the cutout cases that a 130 grain .270 (6.8mm) bullet with a similar ballistic coefficient to the 120 grain .264 (6.5mm) bullet intrudes greatly upon the case capacity of the Remington cartridge, effectively limiting the bullets used in that cartridge to the stubbier 115 grain class of bullets. This presents no problem within the design parameters of the 6.8 Remington cartridge, for it was not developed  as a long range cartridge. The Grendel case can efficiently use bullets up to 144 grains that are superb performers at long range. The 120 grain Remington Core-Lokt bullet pictured intrudes very little upon the case capacity of the Grendel. As a side note, all the qualities that make the Grendel an excellent long range target round, coupled with a high level of retained energy at extended ranges, also makes it highly desirable as a tactical rifle for police and military work.

To achieve the desired level of accuracy, Alexander Arms uses the finest components to build the Grendel. One cannot simply slap a 6.5mm barrel on any AR-15 and achieve a high level of competitive accuracy. The Alexander Arms Grendel rifles use Lothar Walther hand-lapped stainless barrels that are carefully chambered, throated, crowned, and fitted to the upper receiver. Even the throat is specially cut and lapped for increased accuracy.  The upper and lower receivers are precisely fitted, with absolutely no play between the halves.  Alexander uses a special deburring tool to carefully trim the gas port where it engages the bore to limit any bullet distortion as it passes. Most of the Grendel variations employ a one turn in eight inch rifling twist to better stabilize bullets at long range. This allows the 6.5 Grendel to utilize the long, sleek bullets that slip through the air so well to accurately hit distant targets.

Although Alexander Arms makes variations of the Grendel that are purpose-built for target shooting, I am primarily interested in the rifle as a hunting  weapon. Therefore, the rifle sent to me for evaluation wears a heavy, but not too heavy, medium length barrel. Alexander calls this the Entry 18.5 inch rifle. The barrel on my sample actually measures 19.7 inches from bolt face to muzzle, giving almost a full 18 inches of rifling in the bore.  This is a very handy size for a hunting rifle. It has a fourteen inch length-of-pull, and an overall length of just thirty-eight inches. The barrel has a heavy profile, and measures .758 inch at the muzzle. The sample gun weighs in at seven and three-quarters of a pound empty.  After mounting a Leupold Mark 4 4.5 to 14 power scope in a one-piece ArmaLite mount, the balance point is right at the hinge pin, making for a perfectly balanced rifle that feels much lighter than the scale reads. It has a composite smooth black free-floated hand guard, and a flattop upper receiver with a built in Picatinny rail for optics mounting. It has all of the standard A2 type features, including a case deflector and forward assist knob. It wears a very comfortable synthetic rubber pistol grip and has an  A2 type buttstock. The hand guard has two sling swivel studs to easily mount a sling and a bipod. The best feature of the Entry rifle is the superb trigger. Alexander calls it their Tactical trigger; I call it the perfect hunting trigger. It is of a single stage design, and released crisply at just over three pounds on the test rifle. The blade of the tactical trigger is only about one eighth of an inch wide, which provides for a good trigger feel, even when wearing gloves, as hunters often do.

I like the appeal of an AR-15 as a deer hunting rifle. The stock is shaped perfectly to get a good cheek weld while peering through a scope sight, and the recoil is straight back. After firing, the rifle is instantly ready for another shot.  For a tactical rifle, this is very important also, as no movement is required by the shooter to get the rifle ready for another shot.  The straight back recoil allows the shooter to get back on target sooner for a quick follow-up shot if needed, or to engage another target.  The 6.5mm Grendel cartridge gives the AR-15 the power that it has previously lacked for hunting deer and large predators.

As mentioned above, I mounted a Leupold Mark 4 scope on the Grendel. The Mark 4 series is Leupolds tactical rifle scope line, and is one of the finest scopes available for the purpose at any price. The Mark 4 has covered target style adjustment knobs with one-quarter minute click adjustments. The dials are marked for reference, and can be zeroed to suit a particular load and range. The 4.5-14 Precision Long Range scope tested has a Mil-Dot reticle that is very helpful in range estimation with just a bit of practice. The dots are spaced at one milliradian increments, and very good range estimation tables are included in the instruction booklet. This diagram shows the crosshair in detail:

One of the best features of the Leupold Mark 4 PR Scope is the side-focus knob for the parallax adjustment. It is much easier to reach than having to turn the objective lens housing on most other scopes, and allows the use of flip-up lens covers on a parallax-adjustable scope. Being easier to reach requires much less movement on the shooters part. The side focus is a great idea. The Leupold Mark 4 has superb clarity and precision internal adjustments, and is an excellent scope for the Grendel rifle.

The factory loads tested in the Grendel were fired for velocity reading over my PACT chronograph at a distance of ten feet in front of the muzzle. All loads were of Alexander Arms brand. The weather was pretty nasty at the time, with a temperature of eleven degrees Fahrenheit. All velocities are listed in feet-per-second. The chronograph results are posted below:

LOAD VELOCITY
123 Grain Scenar Hollowpoint Boattail 2591
129 Grain Hornady SST 2389
120 Grain Nosler Ballistic Tip 2557
90 Grain Speer TNT Hollowpoint 2768

The velocity readings were very consistent, which proved beneficial when later testing the ammunition for accuracy in the Grendel.   Most accuracy testing was done at a range of 100 yards, with a gusty wind over my left shoulder and a temperature of thirty-eight degrees Fahrenheit.  All shots were fired from a bench using the Target Shooting Inc. Model 1000 rest.  The excellent trigger pull was very helpful shooting accurate groups with the Grendel. I group tested the four factory loads, along with a few handloads that proved to be consistent over the chronograph screens.  I fired three-shot groups with each load. I am interested in hunting accuracy. The first one, two, or at the most three shots from a cold barrel are the most important. The barrel was allowed to cool completely between groups. The handload data will not be printed here, as the loads have not been pressure tested, but proved to be safe in the sample rifle. I checked case head expansion with a micrometer, and compared the results with the expansion of the factory ammo as a guide.  Load data is available from Alexander Arms, and is included with the loading dies. I tested bullets and powder combinations that I thought suitable for deer hunting, and included no match bullets in my testing. I plan a follow-up article later on loading for the 6.5mm Grendel. All group sizes are listed in inches. Accuracy results were as follows:

LOAD GROUP SIZE
123 Grain Scenar Hollowpoint Boattail 0.500"
129 Grain Hornady SST 0.687"
120 Grain Nosler Ballistic Tip 0.937"
90 Grain Speer TNT Hollowpoint 0.937"
Handload #1 with 100 Grain Nosler Ballistic Tip 0.312"
Handload #2 with 100 Grain Nosler Ballistic Tip 0.625"
Handload #3 with 100 Grain Nosler Ballistic Tip 0.500"
handload #4 with Remington Core-Lokt 0.563"

The first four loads listed are Alexander Arms factory loads, and performed very well. The handloads that I fired for group sizes all used bullets that I thought would be excellent deer hunting bullets. The beautiful thing about the 6.5mm Grendel, and all 6.5mm cartridges of moderate velocity, is that there are many good, reliable hunting bullets available. The factory loaded 129 Hornady SST and 120 grain Nosler Ballistic Tip loads should be fine performers on whitetail deer. I made no attempt to duplicate those loads. The 120 grain Remington Core-Lokt is a proven bullet that performs splendidly from the .260 Remington and 6.5mm Swede, and it should do very well at the slightly lower velocities of the Grendel. The bullet that really interested me for deer hunting was the 100 grain Nosler Ballistic Tip. It is listed by Nosler as a game bullet, and is made to perform well at higher velocities. Therefore, I did not worry about it coming apart when fired from the Grendel. Handload #1 gave me the best accuracy, with almost as much velocity as handload #3 using that bullet. I was very impressed by the 5/16 inch group of that handload, and the velocity registered 2780 feet-per-second.  From the Grendel, it is a very flat shooting load, as illustrated in the chart below:

Since this load had proven to be so accurate at 100 yards, I also shot it for accuracy at 300 yards. The air temperature was 58 degrees, with a gentle crosswind from the left. My normal shooting range has a maximum distance of only 110 yards, so I had to improvise a shooting range for 300 yards. I did not have the use of a sturdy bench or the Model 1000 rifle rest, but shot from an elevated deer stand and rested the forearm on the rail. It was difficult, but I finally found a comfortable position and got the crosshair to settle in, and fired a three shot group that measured right at one inch. I was very pleased, to say the least. I then fired another three shot group that printed the same. I quit while I was ahead. That is one-third minute accuracy from this AR-15, from a deer stand! I was ready to hunt.

Since choosing this load to try on whitetail, I have only shot three deer with it. Two were medium sized does, and one was a heavy buck. The two does were shot at ranges of 85 and 92 yards. Both dropped immediately at the shot. Neither even twitched. The buck was across a field as I approached from a ditch. I took a rest over a tree limb, and he fell at the shot without even taking one step.  I lasered the distance back to the ditch at 219 yards.  Another thing that I noticed about the Grendel is that the efficient little jewel is relatively quiet, as far as center fire hunting rifles go. I have either shot or seen shot many whitetail deer. I was very impressed with the quickness that these deer expired. The Nosler Ballistic Tip and the 6.5mm Grendel seem perfectly matched for whitetail. For heavier game, I would probably choose the 120 Core-Lokt, or the Barnes 120 grain XLC. The XLC is long for its weight, and takes up some powder space, so I think that the Core-Lokt might be a better choice. A 100 grain XLC would most likely be perfect, if Barnes would only make a 6.5mm bullet in that weight.

I look forward to more shooting with this rifle, both at the range and in the field. The Alexander Arms 6.5 Grendel rifle is very well suited to the needs of long range target shooters, but I will leave that conclusion to those who are more experienced than I in that area. For police, military, or civilian defensive situations, the 6.5 Grendel shoots flatter and hits harder at long range than both the  5.56 NATO and the 6.8 Remington. It shoots flatter than the .308 Winchester, with energy numbers that even exceed this cartridge at longer ranges with certain bullets. I see the 6.5 Grendel as a dandy little deer rifle, offering a flat trajectory, low recoil, and plenty of power in an accurate and reliable AR-15. Bill Alexander expertly assembles the Grendel rifle from the finest components available, from the excellent Lothar Walther barrel to his own Tactical Trigger.

I have waited impatiently for almost two years for the arrival of this rifle. It was worth the wait.

For dies, ammunition, accessories, and rifle information, check out the 6.5 Grendel options online at: www.alexanderarms.com.

To view the entire line of quality Leupold optics, go to: www.leupold.com.

Jeff Quinn

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Click pictures for a larger version.

 

Alexander Arms 6.5mm Grendel.

 

 

 

 

Alexander Arms' excellent "Tactical Trigger".

 

Free-floated barrel.

 

 

Handguard features two sling swivel studs for easier bipod mounting.

 

 

 

 

Cartridge comparison (left to right): .223, 6.5mm Grendel, .50 Beowulf

 

 

Cartridge comparison (left to right): 6.5mm Grendel, 6.8mm Remington

 

 

Cutaway cartridges (left to right): 6.5mm Grendel, 6.8mm Remington. This illustrates the relative case capacity with bullets of like ballistic coefficients.

 

 

Author tested the 6.5mm Grendel with Alexander Arms factory loads featuring several different bullet types (left to right): 90-grain Speer TNT Hollowpoint, 120-grain Nosler Ballistic Tip, 123-grain Scenar Hollowpoint Boattail, 129-grain Hornady SST.

 

 

Jeff also worked up some handloads for the 6.5mm Grendel. Some of the bullets he used (left to right): 100-grain Nosler Ballistic Tip, 120-grain Nosler Ballistic Tip, 120-grain Barnes XLC, and 120-grain Remington Core-Lokt.

 

 

As can be seen on the accompanying table, the Alexander Arms 6.5mm Grendel is exceptionally accurate with a good variety of both factory ammunition and handloads.

 

 

 

 

 

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