The venerable Encyclopedia Britannica defines the law of diminishing returns as an “economic law stating that if one input in the production of a commodity is increased while all other inputs are held fixed, a point will eventually be reached at which additions of the input yield progressively smaller, or diminishing, increases in output.” Generally speaking, in more colloquial terms, the law of diminishing returns simply refers to a scenario in which the investment required to maintain a steady increase in a rifle’s accuracy, persay, begins to take on an exponential cost. In other words, it is the law that governs why it can cost $500 to double a rifle’s accuracy from 4 MOA to 2 MOA, but doubling the accuracy again from 2 MOA to 1 MOA can cost $2000 or more.
Now, obviously that price tag includes the optic and accessories, but nonetheless the Accuracy International AXMC rifle pictured here is undeniably expensive. In fact, unless you have just a hair over $8,000 to spend on your next rifle, this won’t be it. Having debuted at SHOT Show in 2014, the AX line of rifles are Accuracy International’s first kick at the multi-cal, barrel-swapping can and as such are some of the most expensive rifles in their lineup. Within the AX line there are three disparate models; the long-action AXMC (AX multi-cal), a short-action AX-308 model with the same quick-change barrel system, and an AX-308 with a conventional fixed barrel. To differentiate between these various models, the multi-calibre models have become commonly known as the AX-338MC and AX-308MC, while the fixed barrel model is generally referred to as the AX-308. Obviously, due to the length of the action and magazine well, the AX-338MC can accept both long-action calibres such as 300 Win Mag, as well as short-action calibers, and our test rifle shipped with both a .338 Lapua barrel, bolt and magazine as well as a .308 barrel, bolt and magazine. The AX-308MC is limited to rounds commonly available in short-action tactical rifles, and barrels can be found in a variety of calibre if one looks hard enough, or conversely can chambered for any other round that can fit the AX-308MC’s .308 bolt face.
Beyond that, the AXMC platform brings with it the excellent Accuracy International rifle action, replete with the insanely smooth bolt travel, and the flat-bottomed action that is itself permanently bonded and bolted to the core of the rifle chassis. Inside the action, the AXMC uses a bolt with three bolt lugs, in keeping with Accuracy International’s traditional 60-degree bolt lift, but uses six lugs in total to provide a stronger lockup to deal with the impressive chamber pressures of the .338 Lapua round. The extractor is of the leaf-spring variety and as with other Accuracy International rifles, the safety remains a three-position affair capable of either locking out the trigger alone or locking both the trigger and action. The entire action is topped by a full-length NATO STANAG 4694/Mil Std 1913 rail that runs uninterrupted from the back of the receiver to the end of the handguard, and is tilted 20 MOA on the .308 models and 30 MOA on the long-action AXMC model.
Now, from that regurgitation of specifications, one would assume the AXMC bears little in the way of progress from previous AI rifles, upon which the AXMC is certainly based. Even the six-lug format is hardly new for Accuracy International, having been introduced with the famous (with video game players, at least) Arctic Warfare rifle first produced in the early ‘80s. However, while the action is definitely familiar, the rest of the rifle is very much new-tech.
The most obvious difference between the AXMC and most previous Accuracy International rifles is the chassis-style format. Having made their name using a more conventional rifle-in-stock arrangement, the AXMC’s tubular handguard and skeletonized stock looks thoroughly modern, and offers many benefits to those that need to mount additional accessories to their rifles. With an uninterrupted top rail, soldiers and law enforcement officers can mount night vision optics cleanly and easily in front of their standard optic, while the KeySlot accessory rails at 3-, 6-, and 9-o’clock allow additional lengths of picatinny rail to be mounted where the user needs them for bipods or other accessories.
Now, a note on KeySlot: It is not KeyMod. KeyMod accessories are not compatible with Accuracy International’s patented KeySlot system. Although predating the development of KeyMod, KeySlot remains the intellectual property of Accuracy International, which has ensured it remains far less common than the open source KeyMod system. This means all AXMC owners should expect to turn to Accuracy International for their accessory rails. This means all AXMC owners should expect to pay a pretty penny for their accessory rails. Wait; did I just say the same thing twice?
But while the handguard may be the most obvious departure from Accuracy International’s previous rifles, the big party piece is a small machine screw located at the front of the action. Loosening this screw with an allen wrench that stows handily in the cheek rest releases the action’s grip on the barrel. With that done, removing the barrel is as easy as simply unthreading it from the receiver, and sliding it out of the handguard. Installation of a new barrel is simply the reverse. Headspacing is handled by a large shoulder machined into the barrel shank that butts up against the front of the receiver. Tightening the machine screw again secures the barrel in place. If the calibre’s base diameter is changing (in our case from .338 Lapua to .308 Winchester), then the bolt is also removed and replaced with the correct bolt, as is the magazine and associated magazine well insert. The entire process takes no more than a few minutes if done methodically, and although there is some degree of POI shift it is not dramatic (in our case little more than a few MOA) and more importantly, proved 100% consistent. In other words, our POI shifted the exact same way every time I switched barrels, meaning that I could switch from .338 Lapua to .308 Winchester, dial in the expected POI shift, and bang targets on our first shot.
Finally, the rest of the revisions are done with the aim of making the big rifle more shooter-friendly. First off, the bottom of the action has been excised on the left side around the magazine well, in order to make it possible to remove the big single-stack .338 Lapua magazines without tipping the butt of the rifle up to clear the magazine. Unlike most other Accuracy International guns, the stock folds on the right side of the gun, which not only makes sense from a carrying perspective (making the left side of the gun totally slick), but also retains the bolt as the stock secures the bolt in the forward position. Of course, like all AI rifles, it’s probably operating on the most stout hinging mechanism in the industry, and when deployed the stock is indistinguishable from a fixed stock. Equally expected is the massive amount of adjustment available, with the stock allowing for alterations to the length of pull, recoil pad height, and comb height. AI should be commended by the method of adjustment as well, as all adjustments are accomplished by simple thumb screws, but are also incredible solid when fixed in place.
Which brings us to the good part: The shooting. Obviously shooting any Accuracy International rifle is a proper first rate treat; these things are the veritable Ferrari’s of the long range world. And to shoot the top of the line AXMC model? Well, that’s one of those experiences that mixes excitement with trepidation, if only due to the overall price tag of the thing you’re putting up to your shoulder. After all, it’s not every day one gets to shoot a gun worth more than the average economy car.
Step one to shooting the AXMC is to simply get comfortable. Designed for dedicated military and law enforcement snipers who may need to remain in a shooting position for hours, the gun’s various adjustments make it relatively easy for almost any shooter to adopt an incredibly comfortable shooting position, and getting the gun set up for comfort and the appropriate eye relief to the Schmidt and Bender PMII 3-20×50 optic didn’t take more than 15 minutes… and that was moving slowly. Again, this wasn’t a test rifle that I were overly keen to accidentally cross-thread an adjustment screw on.
With the shooting position locked in, and the optic zeroed to the installed .308 barrel, I loaded five rounds into the ten round single-stack magazines that AI has become famous for and commenced shooting. To say the gun was nothing short of an epiphany would be to a lie. I’ll stop short of claiming that the heavens parted, a single beam of light shone upon its glorious muzzle, and a host of angelic voices raised themselves in perfect simultaneous chorus… but it was damned close. Shooting a perfect cloverleaf at 100 yards with Federal Gold Medal Match the AXMC scoffs at such classifications as “MOA” or “sub-MOA.” This thing is a laser. If you put even one round into the target that isn’t touching your previous rounds, it’s impossible not to feel as if you’ve somehow failed the AXMC in some way; as if it was some sort of sentient creature to which you must measure up and declare yourself worthy.
So what makes it so accurate? Well there’s obviously the mechanical benefits of a gun that’s been assembled by a team of engineers of the ilk that Accuracy International employs. But we’ll talk about that later. The other component to this gun’s supreme accuracy is the way Accuracy International has considered the human element in a way many gun manufacturers don’t. The pistol grip is perfectly formed to grip your hand just as much as it was designed to be gripped. That lets you keep a relaxed hand on the controls, keeping any wayward muscle tension from effecting your aim. Likewise, all that adjustment in the stock makes sure your shoulder and head support the gun with your natural skeletal structure and shape, rather than requiring your body contort around the gun and be forced to use muscle to support the rifle. The massively heavy barrel profiles on both the .338 and .308 barrels, and the huge muzzle brakes fitted quell almost all recoil to the point that the rifle moves so little that even an inexperienced shooter is naturally able to watch their round’s impact through the optic. And the trigger… well… although it’s not quite conventional (due to the manner in which it adjusts, the trigger has a lot of overtravel) it is perfectly suited to the task at hand. With a smooth swing through the first stage and a nice, clean, light break it somehow naturally encourages the shooter to concentrate on a gentle squeeze. Don’t ask how a trigger can make you remember to practice proper trigger control… just know that somehow, Accuracy International figured out how to do exactly that.
Which brings us to the elephant in the room, and the aforementioned source of the AXMC’s inherent mechanical accuracy: The law of diminishing returns. See, like all Accuracy International rifles, the AXMC is not designed with the civilian shooter in mind. Nay, it in intended for a slightly more professional audience; namely those upon whom the balance of life and death could literally hang upon the outcome of a single shot. As a result, the AXMC’s design, manufacturing, and assembly has more in common with the aviation industry than most conventional manufacturing processes, as the acceptable failure rate for their products is 0%. Other companies with a less demanding customer base can lean upon post-sale service systems like life time warranties and the like to imbue a sense of quality in their products, or perhaps take pride in a good customer service and repair network, but for companies like Accuracy International none of that will help when someone may be relying on one of their products to literally survive.
As a result, the AXMC is in many ways the physical embodiment of the law of diminishing returns. For many civilian shooters and even some professionals, the incremental steps Accuracy International has taken towards absolute reliability and perfect precision do not justify the expense incurred in the pursuit of those lofty goals, and for those shooters there is all manner of Savage, Remington, and even Sako rifles (not to mention dozens of other, smaller manufacturers). But for the shooters that cannot accept the notion of compromise, the work Accuracy International does with rifles such as the AXMC is as indispensable as it is invaluable. And while I hope to never find myself in the situations faced by those sorts of individuals, shooting a rifle as incredible as the AXMC provides a brief glimpse into precisely how awesome something can be when the law of diminishing returns are absolutely and utterly ignored.