The Geissele Freedom Rifle in 6mm ARC: Complete Review

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When Hornady announced the 6mm ARC, they were allowed to say it was developed for and fielded by a “notable Department of Defense (DOD) entity.” That same entity needed a reliable rifle from which to shoot their new cartridge, and the first rifle they selected was the Geissele Freedom Rifle (GFR) seen here. They have since asked for and received other GFR models, but more on that later. Geissele made the first GFR almost three years ago, but it went through an exhaustive development cycle prior to fielding. After development, Geissele had been busy building these guns for that DOD entity. They’ve just about caught up, so the GFR will be available commercially about the time this article hits the newsstands.

SOCOM DEVELOPMENT CYCLE

It’s obvious that the GFR hasn’t been fielded by conventional DOD elements, so these rifles are quietly serving somewhere in Special Operations Command (SOCOM). That accomplishment means a lot more to us regular consumers than just some fun fact to bring up with fellow gun nerds. In order to see fielding within SOCOM, there is a development cycle that the GFR went through that benefits all of us commercially. I have friends that served in the units that can purchase rifles like the GFR, and they’ve explained the process to me. When the unit tests a rifle prior to fielding, they purchase about 10 samples. They do all their internal testing for accuracy, reliability, etc., and then they pass them off to a dedicated testing group that runs each rifle to 50,000 rounds and logs every stoppage and malfunction. That process generates a pile of paperwork that is usually over a foot tall, and then all that data goes back to the manufacturer for design changes and improvements. Few companies have the time, knowledge, or money to recreate this. But SOCOM has the resources and trailers full of ammunition to execute a program like that. I get excited when guns like this become commercially available, because even though they’re “new,” these guns are more thoroughly vetted and tested than anything else. The 6mm ARC is a new cartridge that offers a lot more capability than the 5.56, so having a rifle that’s proven itself and is chambered in this cartridge is a big deal. The GFR is the only “go to war” ready 6mm ARC made. The details behind the GFR are as interesting as its SOCOM story.

INSIDE THE RECEIVERS

One of the biggest challenges to chambering an AR-15 in 6mm ARC is the size of the bolt face. An AR chambered in 5.56x45mm has a bolt face diameter of .378 inches. The 6mm ARC requires .441 inches. Just hogging out an AR-15 bolt to fit the 6mm ARC leaves a thin band of steel around the cartridge case head when chambered. Cutting away that steel removes precious material that keeps the bolt’s locking lugs (especially the ones on either side of the extractor) from shearing off after thousands of rounds. Geissele started with the material originally specified for AR-15 bolts, which is Carpenter 158. Bill Geissele told me, “It wasn’t uncommon back then for design drawings to not only call out the material but also the supplier. That way, you knew you were getting the good stuff.” Geissele started with the good stuff and then looked for ways to make it better. Carpenter Technology is only about 45 minutes from Geissele Automatics, so Geissele worked with them to find a better starting point.

The Achilles heel of Carpenter 158 is the presence of sulphur and phosphorus in the steel. Those elements are necessary for the material to machine easily, but they also create an irregular grain structure that makes it easy for cracks to form. Geissele worked with Carpenter to create Carpenter 158+, which is a re-melt. Once Carpenter makes the steel, they melt it a second time to burn away more of the sulphur and phosphorus. There is enough in the steel to machine it but far less opportunity for cracks to form due to the reduction. Geissele then takes the 158+ material and forges it into bolts. The forging process eliminates tiny air bubbles that can form in billet and also hammers the molecules into alignment. Cracks have a harder time forming when the molecules align. The end result is a bolt far stronger than anyone else’s and one that is capable of surviving the robust firing schedule selected by SOCOM. Any AR-15 chambered in 6mm ARC would benefit from having the Geissele bolt. The receivers Geissele uses on the GFR rifles are also unique. The most obvious addition is a steel insert riveted in place that functions as a steel cam race. Most of us have seen the cam path on a regular aluminum receiver that’s had a bunch of rounds through it. The steel cam pin chews away the aluminum and beats up the pathway over time. Installing a steel insert prevents rapid wear and prolongs both the life and reliability of the upper receiver. The lower receiver houses Geissele’s Ultra Duty lower parts kit. These are my favorite parts kits because of the quality pins and springs they use. The kit also includes the Maritime bolt catch, which is cast from stainless steel. The Maritime catch has bigger contact patches for easier manipulation, but it is also much more robust and corrosion-resistant than the traditional mil-spec counterpart.

MAGWELL AND MAGAZINES

Geissele used a lot of secret sauce on these areas of the GFR to get it to function with total reliability. Anyone who has ever had an AR-15 chambered in 6.5 Grendel knows the struggle of getting magazines to feed well all of the time. This is where Geissele and the SOCOM development cycle made some beautiful music together. The first step was to start making magazines, since no available magazines performed reliably all of the time. Geissele eventually selected stainless steel bodies covered in a nitride finish along with stainless-steel springs. It took two years of research and development to get the magazines correct. Deciding where and what depth to put the ribs that seat against the cartridge shoulder, shape and length of the feed lips, and follower design all took multiple iterations to perfect. The whole time, SOCOM was pumping rounds through both magazine and rifle to assess performance.

One touch in the magazine well that I find particularly elegant is the front of the triggerguard. A casual glance at the triggerguard and lower receiver leaves the impression that it’s just regular versions of each. Close inspection of the front of the triggerguard shows that there is a small steel insert, and both the insert and guard protrude slightly into the magazine well. Geissele did this as an index point for the magazine to create the ideal feed angle for how the magazine presents the cartridge to the chamber. The magazine still drops free and is easy to insert, but once installed, spring tension holds the magazine against this index point. The steel insert ensures the aluminum triggerguard doesn’t wear and alter the angle over time. It is as thoughtful a refinement as I’ve ever seen on any AR-15. While the Geissele magazines are ideal for 6mm ARC and the GFR, there is no guarantee they will pair well with regular AR-15s chambered in either 6mm ARC or 6.5 Grendel. The tolerances found in other AR-15s are unlikely to miraculously stack in favor of utter reliability. However, they are the perfect complement to the GFR. They are available in 15-, 20-, and 30-round capacities.  

BARREL MAGIC

The 18-inch barrel on the GFR is made from stainless steel, is five-groove, has 5R rifling, and has a twist rate of 1:7.5. This barrel is made by Geissele and is cut-rifled for maximum accuracy. Making any barrel is difficult, but cut-rifling is the most time-consuming process. I mentioned to Bill Geissele what another manufacturer told me when speaking about bringing barrel making in-house; they made really expensive scrap for the first year. “Our experience was very similar,” said Geissele. They have obviously figured it out as the accuracy testing results in the attached table demonstrate. The gas system is unique to the GFR. Instead of one single gas port, there are three ports spaced around the circumference of the barrel. Geissele refers to it as a phased array. Instead of one big gulp of gas to cycle the rifle, the first port unlocks the bolt and starts the carrier moving; the second hit shoves the carrier along; and the third push ensures the bolt carrier moves all the way to the rear. Spreading out the gas system push allows Geissele to have a lot more control over the gas system, ensuring the rifle is reliable without being overgassed. The gentle ramp up of gas also means that recoil is more of a push and is as minimal as possible.

Geissele has been making the GFR for military contracts for a while, but they’ve ramped up production enough that the Maritime Recce is available commercially. There are also new models coming in the future. The next up is the Stratomatch, and it’ll have a 20-inch barrel with a heavy contour designed for competition shooters. After that will come a 16-inch, yet-no-be named model in the summer, and the 14.5-inch rifle will come at the end of the year. All will have the features described herein, just with different barrel lengths and weights. The road to the GFR started when SOCOM went looking for a rifle that had more range and lethality than a 5.56 AR, but they were tired of large-frame, .308 Winchester rifles and that family of cartridges. SOCOM briefly flirted with the 6.5 Grendel before Hornady said to give them a chance to create exactly what they needed. That cartridge was the 6mm ARC, and the Geissele GFR is the only rifle purposefully designed to fire it. The creation of the GFR was done with a huge amount of testing by SOCOM, the best third-party verification any of us will ever see.

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