Beyond556.com

DECEMBER 2003

“A Shooter” - Arne Brennan, CompetitionShootingSports.com

Historically, the AR15 / M16 has not been without controversy and critics. As a military rifle, during early use in the Vietnam War, the M16 suffered from functioning problems due to a change in propellants and improper training of soldiers regarding cleaning and maintenance. Lessons were learned, refinements made and the M16 platform evolved into one of the most prominent firearms in military history. However, the M16 to this day is not without criticism, not so much due to the rifle, but because of the 5.56 NATO cartridge, that lacks the long-range effectiveness of the 7.62 NATO cartridge used in the M14 and other military small arms.

In the civilian market, the AR15 for many years has been considered a casual target and small game rifle again in large part due to its standard chambering in .223 Remington. In formal target competition, it was cast aside as not being a viable option compared to the M14 and it’s civilian counterpart, the M1A, using the 7.62 NATO / .308 Winchester cartridge.

In the 1990’s, the AR15 started to appear in the competitive shooting arena and it slowly began increasing its numbers in service and match rifle competition. Use of the AR15 reached a beginning in 199X. During that year, a change in leadership at the US Army Marksmanship Unit mandated change to the current US Army standard issue rifle for use in National Match competition. Following the US Army Marksmanship Unit, various other military shooting teams adopted the AR15 platform for National Match Competition as well. As the 21st century arrived, the AR15 / M16 took the dominant position in terms of numbers at many high power competitions including the NRA National Matches at Camp Perry.

While the AR15 has attracted an increasing number of competitive users, its use of the .223 Remington cartridge still limits use in long-range competition. To illustrate this point, at 600 yards, the AR15 in 223 Remington requires use of specialized 80 and 90-grain bullets seated beyond magazine length to be competitive. While this adaptation has allowed the AR15 to become a prominent contender in across the course competition at ranges from 200 to 600 yards, when competitors are given a choice of platforms and cartridges, the AR15 is often passed over in favor of cartridges such as the 6mm BR Norma, 6mmXC, and 260 Remington in bolt action rifles such as the Tubb 2000 or semi-automatic rifles such as the Armalite AR10.

Over the years, a number of AR15 competitors have attempted to overcome this trend by seeking alternative cartridges for use in the NRA match rifle category. In 1998, I like those before me, began this search for an alternative to the 223 that would provide an edge in competitive shooting. In addition, I wanted to explore the idea that a cartridge with such a competitive edge could also be an effective hunting cartridge for whitetail deer, feral hogs and a variety of other game animals.

In the past, one of the most notable alternative cartridges for the AR15 has been the 22 and 6mm PPC. In reviewing these two options, the 22 PPC allowed use of heavy 80-grain bullets needed for 600 yards, but in a magazine length loading. This capability gave a considerable advantage because in theory, one load could be shot across the course simplifying ammunition requirements. However, I didn’t feel the 22 PPC using 80-grain bullets would provide the edge I was seeking and it did not fulfill my hunting capability requirement.


In contrast to the 22 PPC, the 6 PPC was able to fulfill my dual role requirement by using bullets such as the Sierra 107 grain Match King for competition and Nosler Partition bullets in 85, 95 and 100-grain weights for hunting. However, one thing bothered me about the 6 PPC. In my research, I discovered it was necessary to seat the 105-107 grain match bullets back in the case to be within the 2.255-inch length restriction or the front of the magazines needed to be notched to optimally seat the bullet and gain the maximum powder capacity. The thought of notching magazines had zero appeal so before going further with the 6 PPC, I decided to think out of the box.

I knew that Sierra made a 6.5mm 107 grain Match King and Lapua made a 108 grain Scenar and due to the increase in bullet diameter, theses bullets were slightly shorter then their 6mm counterparts. Therefore, use of these 6.5mm bullets would not require seating the bullet back in the case or notching magazines. Interestingly, I found that Lapua also offered a 123-grain Scenar that was the same length as the lighter 108-grain Scenar and had a similar ballistic coefficient to the 6mm 105-107 grain offerings. It became clear that by increasing the caliber to 6.5 mm, I could equal the ballistics of the 6 PPC with the 107-grain Sierra and do so without notching magazines or seating the bullet back in the case. In addition, 6.5 mm was easily considered an effective hunting caliber with multiple controlled expansion and polymer tipped bullets in the 100-125 grain weight range available. In theory, it would be a perfect multi use cartridge provided I could equal the velocity the 6 PPC achieved with 105-107 grain match bullets.

In mid 1998, I made the commitment to go with a 6.5 mm version of the PPC and contacted JGS Tool (PS advertiser) to construct a reamer. Since there were no standards for or published history on the 6.5 PPC, JGS Tool constructed a reamer with no throat and provided me with a separate 6.5 mm throat reamer to allow the gunsmith to cut the throat to proper length for my application. Using the final reamer dimensions, Redding constructed a bushing type full length-resizing die. Only thing left was to take the leap of faith and begin construction of a rifle. After speaking with numerous gunsmiths, Scott Medesha of Medesha Firearms (PS Advertiser) undertook the project and delivered a custom rifle in late 2000.

As many readers will appreciate, load development for a wildcat cartridge can be a time consuming experience and this is especially true for a cartridge such as the 6.5 PPC that had no published information available. Taking advantage of the openness of the competitive shooting community, I contacted Dr. Lou Palmisano in early 2001 and discussed my project with him and his theoretical knowledge and guidance as invaluable. In addition, multiple other competitors offered their guidance and knowledge at various points in my project including David Tubb, Derrick Martin, John Holliger, Lew Tippie and Jeff Rost.

As load development and testing continued, I discovered the 6.5 PPC was very effective and accurate using medium weight 6.5 mm bullets. My initial goal of achieving 2650 fps was surpassed as I developed loads using moly coated Cauteruccio 128 grain bullets achieving 2750-2800 fps. My project was a success, but little did know that it was to take a new direction.

In early 2002, I contacted Loather Walther to speak with them about getting a barrel blank. Rather then just sell a barrel blank; they spent time learning about what my application to be sure that I got their best barrel configuration for my needs. Interestingly, during the conversation, they kept introducing Alexander Arms to the discussion. I had heard of Alexander Arms through a friend of mine who was interested in their 50 Beowulf cartridge for hunting, but had never given much thought to it because I was primarily a long-range paper puncher. Loather Walther introduced Alexander Arms into the conversation so often with the suggestion that I speak to them; I finally had to tell them I really had little interest in a 50-caliber AR15 cartridge. Their response was they knew that, but they were positive that I would really enjoy speaking with Bill Alexander. Ironically, a few days later, the friend with an interest in the 50 Beowulf asked if I could learn more about the Beowulf to help him decide whether it was a good direction for him to take. I agreed to find out what I could and picked up the phone and called Alexander Arms and spoke to Bill Alexander about his 50 Beowulf creation. The point came where discussion on the Beowulf was almost complete and I told Bill that I had spoken to Loather Walther and they were insistent that I call him, but I really didn’t know why since I was focused on my 6.5 PPC AR15 match rifle. A few moments of silence later, Bill Alexander response to this was “You have a working AR15 in 6.5 PPC?” I said yes and what had been a 15-minute conversation became an enthusiastic discussion lasting another 3 hours and a shooting relationship that continues to this day.


“A Designer” – Bill Alexander, Alexander Arms, LLC.

Wow how many bullets are in that group? The shooter from the next bench was examining the ragged hole in one of the test targets and was obviously now very interested in what he had previously considered as one of those stupid AR's you can't hunt with. I was sat at the local public range on a Wednesday evening setting up one of our new 6.5 Grendel rifles for the first announced public outing at Blackwater training facility. As usual the rifle was performing well which, while I had come to expect no less, was reassuring before putting the gun in front of such a critical audience.

The 6.5 Grendel is the newest rifle and cartridge in the Alexander Arms lineup and is scheduled for release at the 2004 SHOT show. Rifles, brass, dies and ammunition will all be made available at this time. The rifle from a designer’s viewpoint is a pinnacle for what may be achieved within the confines of the AR15 style chassis and for once the disparate factors of mechanical function, internal, external and terminal ballistics are all working in harmony rather than being a series of trade offs and compromises. The cartridge itself which is a close evolution of the 6.5mm PPC is the ideal length to seat long ogive 120 grain and 130 grain bullets to magazine length. Any more length and the bullets would sit too far back into the case with erratic neck tension, any shorter and the bullets would sit out too far and again that troublesome neck tension problem occurs. The case body is perfect in length to stabilize the cartridge in the magazine and prevent tipping without having to resort to special and normally jam prone followers. Even better it is the maximum diameter to allow a double column feed although a new magazine must be used but it still fits in the magazine well which is the fixed parameter.

Powders suitable for the bullets in this case size typically occupy close to 100% load density. Measure the internal pressures when firing such loads and the instruments report back mean average pressures in the 42,000 psi range. Given that the rifle will operate and pass long term fatigue tests at pressures of 45,000 psi the internals are being nursed happily along causing sighs of relief among both engineers and insurance agents. At the muzzle a steady velocity of 2600 fps is registered which is not to shabby for a 123 grain bullet from an AR. Shoot a sting of 10 rounds however and something magical happens. Velocity figures with corresponding pressure curves do not change shot to shot. Typically a 10 shot sting has a maximum spread of only 2 fps and the bullets pick a single clean hole in the sighting board. For the rifle itself the steady pressure allows the gas operation to be finely tuned such that the bolt carrier impulse is identical shot to shot and the parts move at close to optimum design speed. Ejection patterns are consistent and the whole reloading cycle becomes reliably and repeatable as the parts are always doing the same thing at the same speed.


One of the great things about any rifle in 6.5mm caliber is that the bullets have high coefficients of drag (Cd) and because of this they shoot flat and really buck the wind. The 6.5 Grendel is no exception. The 123 grain bullet with the modest 2600 fps muzzle velocity has a Bc of 0.547 which in layman’s terms means you can shoot 1200 yard targets and at 600 yards tennis balls are easy prey with a scope adjustment of only 14 MOA. The accuracy and the flat shooting characteristics also assist the terminal ballistics and make the rifle a good choice for hunting. In much the same manner as the .243 Winchester, the gentle recoil assists accurate placement of the bullet. Mild muzzle velocities will not blow up bullets that expand well but the retention of down range velocity ensures that good expansion will happen. A 120 grain Nosler Ballistic tip is typically traveling at 2600 fps at the muzzle. At 175 yards the velocity is 2275fps. In ballistic gelatin this bullet will penetrate 18” and expand to .51” diameter with a 75 % weight retention. The recovered bullet has lost the plastic tip and a little of the front of the jacket but the mushrooming is picture perfect with no core separation. For interest I have also sent a few target bullets downrange into ballistic gelatin picking out the 108 grain Scenar which I believe would make a great varmint bullet for extreme range shooting. With a Cd of 0.478 the bullet has a muzzle velocity of 2750 fps and at the 300 yard mark penetrates 22” of gelatin with a .43” diameter and a 64 % weight retention. In this instance I was too close to get a realistic idea of what the bullet could do, but calculations show the load will easily reach the 1000 yard. Back in the real world these bullets slice through 4” pine posts at the 900 yard marker so there is still plenty of energy

My association with the 6.5 Grendel or to be more accurate what was to become the 6.5 Grendel goes back to early 2001. During this time I was finalizing the design for the .50 Beowulf cartridge and rifle which was the first mainstream product of Alexander Arms. The Beowulf is anything but refined. Using a straight case with a fully rebated rim this cartridge throws close to 1 oz slugs at 1900 fps. Accuracy is generally good and everything else is mastered by the raw power. Beowulf is adept at moving turf about and will kill just about anything inside a 100 yard radius, all out of a 7 lb AR with a short 16” barrel. What it does lack is that ability to reach out to those targets that are just dots on the horizon and as an AR style rifle builder who specializes in unique calibers this was an ideal niche in the market.

The initial designs for the 6.5 Grendel were sketched out at a business lunch on a napkin. To be truly any use the design had to be able to be used for a wide variety of hunting as it is my opinion that a rifle that cannot be used for such is simply a stick; and it must be fun. Being a designer for a rifle company precludes most formal shooting on a time basis so I have become an avid plinker. Targets like tin cans, golf balls and charcoal briquettes demand extreme accuracy as ranges increase and a rifle that can master such targets will promote good marksmanship. The down side is that plinking is addictive and such a rifle will also increase ammo expenditure.

With much of my time and all spare cash tied up in Beowulf production it was over a year before I returned to finalize work on the new rifle. During that time I had idly tinkered on the design. A wide variety of calibers had been tested from .243 through .30 with the most promising sitting between .25 caliber and 7mm. Of these the 6.5mm had the most efficient bullets in the weight range that could be effectively launched from a cartridge that would fit an AR so the cartridge case size and caliber was more or less set. All I had to do was match it to an existing cartridge then produce the drawings for the cases, dies, reamers and the barrel. Calculations indicating the time vs pressure curve for the cartridge were performed and the position for the gas port was set. The details of such work are generally boring so I will not repeat then here but suffice to say the resulting cartridge was a 6.5mm PPC with minor changes to the neck and shoulder to adapt the case to the rigors of semi automatic feeding.


Every now and then an engineer gets lucky. It was early in 2002, I had the designs for a new rifle out to contract and I was holding my breath that the damn thing would do what it is supposed to. A phone call was passed through to me as the customer wanted technical information on the Beowulf rifle he was looking to purchase, having been referred by Lothar Walther. We spoke for a while regarding the Beowulf then he mentions he has a 6.5mm PPC wildcat in an AR15. The rifle works well but the magazines are troublesome. I have the whole population of the US who could ring about a rifle but I get the one guy who has actually built what I have been working on. I wouldn’t bet beer on those odds. Suffice to say the phone call lasted longer than expected and Arne Brennan, who was the customer, has become a regular conspirator in the work to get the 6.5 Grendel to market.

The outing at Blackwater was a complete success. The Grendel exhibited an outstanding level of accuracy and was a favorite with those who shot it. With input from a wide number of sources including Lapua, who will be making the brass, David Fortier of Primedia who both shot and wrote about the first test gun, and Arne who continually tested components to compare results, the 6.5 Grendel is now a reality. My work led me to the design looking for an AR based hunting rifle that could perform at range, Arne arrived at the same design in the quest for a better competition rifle and we both followed in the footsteps of Dr Lou Palmisano who had worked with the 6.5mm PPC for 300m bench rest competition, that is true flexibility. Is it a good rifle? I will let the shooters and hunters make that decision, I don’t think anyone will be disappointed