Accuracy International AX50

Accuracy International AX50


ABOVE: Accuracy International AX50 .50BMG rifle was designed with long range accuracy in mind.

Accuracy International (AI) has been a well known entity in the precision rifle marketplace since the mid 1980s. AI’s innovations have shaped and influenced the precision bolt action genre of weapons. Much of this stems from AI’s non-typical background for a firearms firm. AI’s founders were competitive marksmen, one of them an Olympic gold medalist and World Champion. AI rifles stemming from this target background was unique in the 1980s when the company was founded. Up to that point sniper rifles were converted hunting or existing service weapons. Accuracy International started with a clean sheet of paper with precision as the guide line. This is something we take for granted today, but was revolutionary when the AI platform arrived on the scene in the mid 1980s.

Accuracy International’s emergence stemmed from the British military’s call for an updated sniper rifle after the 1982 Falklands War. The existing British L42A1 had only been in service since 1970. However, the L42A1’s bolt action design stretched back to the turn of the 19th-20th Centuries. The Falklands War fully illustrated its weaknesses in terms of the wood stock warping compromising accuracy and other issues compromising performance. Accuracy International was the surprise newcomer winner of the search for the L42A1’s replacement. Their rifle was designated the L96 and entered service in 1985.

Nightforce ATACR 5-25x optic attached to the AX50. The red circles are blow out plugs intended to protect the shooter in from case failure.

Rather than a traditional wooden wood or fiberglass stock, the AI L96 was based on an aluminum chassis. All other components, including the receiver, were bolted directly to this chassis. The Accuracy International receiver is bolted with 4 screws and permanently bonded with epoxy material to the aluminum chassis. The heavy walled, flat bottomed, flat sided receiver is machined in-house by AI from a solid piece of forged carbon steel. Two polymer panels with either a thumbhole or pistol grip configuration were also attached to the chassis.

The Accuracy International product lineup has evolved over time. This stems from user feedback as well as responding to improvements in manufacturing materials and methods. It is not sound practice for any business to resist change or better methods of doing something; this smacks of institutional stagnation. Accuracy International does not suffer from this as evident with the emergence of their AX and AT series of rifles in recent years.

The AI rifle evaluated for this article is the AX50 chambered in .50BMG (12.7x99mm). As befitting the cartridge it is intended to harness, the AX50 is a scaled up bolt action dwarfing typical rifles. The Accuracy International AX50 measures 54 inches long and weighs 27 pounds empty. A folding stock reduces length to 44 inches for transport. The 27 inch 1:15 twist barrel has a triple chamber muzzle brake attached to mitigate recoil. The match barrel is free floated and secured to the action via large 39MM diameter threads. The AX50 is fed from a five (5) round detachable magazine. A night vision mounting rail is available. The rail is fitted to the slotted forend that surrounds the barrel, allowing for a forward mounted night vision device to be placed in front of the day optic.

AX50 six lug bolt shown next to an AR15 bolt group for comparison’s sake to illustrate size.

The AX50’s 30MM diameter bolt has six locking lugs and AI’s field proven one-piece extractor. The six lug design allows for a short 60 degree bolt handle lift to unlock the action. The AX50’s high grade steel action is flat bottomed with integral Picatinny rail. As per the original AI L96 rifle, the AX50’s action is bolted to the aluminum chassis along its entire length with being fitted with a full width recoil lug to prevent movement ensuring zero is maintained in all conditions. The AX50’s bolt action is comprised of a one-piece bolt body and receiver constructed from a solid bar of steel. The six-lug action is the heart of the rifle. The lugs are arranged in dual three lug sets around the bolt’s body giving the AX50 extra rigidity and strength for greater precision. The oversize bolt handle and smooth passage in the raceway allows for minimal disturbance when the rifle’s bolt is worked allowing for fast follow-up shots when engaging multiple targets; quite a feat considering the length and girth of the .50BMG round. In the AX50, two soft aluminum pressure release ports/plugs, colored bright red, are provided to minimize blowback danger in the event of cartridge failure. With the forces associated with the .50BMG, this safety measure is be appreciated and not to be taken lightly. The pressure release plugs are replaceable so the rifle can often be repaired and not rendered a total loss in case a cartridge failure is experienced. The AX50 has an adjustable two stage trigger with a large sear engagement before the first stage is taken up to minimize the risk of accidental discharge. Trigger pull can be set between 3.3 to 4.4 pounds.

The AX50 stock features an adjustable comb for proper eye alignment and cheek weld. Length of pull is adjusted via removal buttplates per individual shooter needs. The AI stock is rock solid with design characteristics making it conducive to long range shooting from the prone position using sand bags or bipod. The forend handles bipods or sandbags with equal aplomb. The AX50’s stock contributes to the ruggedness of the rifle ensuring that a key element of a precision rifle is met; accuracy to be constant and repeatable no matter the conditions.

The Accuracy International AX50 stems from an earlier AI rifle chambered in .50BMG, the AW50, which was introduced in the late 1990s. The AX50 is a result of requests from military end users for a more accurate anti-material weapon. The operative wording here is the emphasis on increased accuracy. The .50BMG’s power is legendary since it was created by John Browning. Anecdotal history has Browning creating the .50BMG by scaling up the 30.06 service round at the behest of General Pershing. The purpose of the .50BMG was to serve in both an anti-aircraft and anti-vehicle role with the advent of the first tanks and armored cars that began roaming the battlefield at the end of WW I. Browning’s .50BMG, typified by its chambering in the M2 “Ma Deuce”, had always been thought of as a either a crew served weapon or something better fitted to a vehicle or similar platform in order to tame its power since its introduction. While there were early attempts to create a shoulder fired .50BMG rifle, this genre has come into its own since the mid 1980s and especially flourished over the last few years with several examples of production rifles being available. World events in the 1990’s, Desert Storm, Balkans et al, transpired to give a major impetuous towards acknowledging the increased role possible with shoulder fired .50BMG rifles.

AX50 ideal platform for long interdiction of personnel or material.

While transportable by an individual, the Accuracy International AX50’s size makes it more of a fixed position platform; perfect in an over watch role, especially with its extended effective range and power. One role it has been pressed into is more of a close range weapon found at checkpoints and gated entrances to bases/facilities. Developments in .50BMG ammunition are keeping pace with the rifle component of the platform. This serves to wring even more range and lethality from the AX50. Nothing will shut down an engine block faster than an incendiary/HE Raufoss Mk211 .50BMG round if a driver is not complying with approach procedures. The big AX50’s aesthetics instills a certain sense of purpose. The purpose is allowing for one rifleman to dominate his space on the battlefield against a myriad of targets not possible by any other centerfire cartridge weapon. The AX50 is a weapon with unsurpassed power and effective range for a shoulder fired weapons. Accuracy International’s manufacturing quality and attention to detail provides an accurate, rugged, and reliable weapon that wrings the utmost performance out of the .50 BMG capabilities with the AX50.

The AX50 brings together individual high quality components into one 27 pound package. Along these same lines a Nightforce ATACR 5-25x56MM (34MM tube) was mounted on the AX50 via Accuracy International base/ring unit. Nightforce is a noted high end optic manufacturer with numerous products in use with elite military and police forces around the world. As with any purchase involving gaining a tactical advantage, it is all about perceived needs versus cost. The Nightforce ATACR features multi-coated ED glass. Based on research for this article, ED (Extra Low Dispersion Glass) glass prevents or lessens chromatic aberration because it concentrates and directs the wavelengths of light more effectively. Generally speaking, the better the aberrations are controlled the cleaner and brighter the image will appear. This is especially important at long range high magnification observation. ED glass is usually reserved for premium optics due to the cost associated with it. Other notable Nightforce characteristics of the Nightforce ATACR optic are a second focal plane reticle, ZeroStop elevation adjustment, .25 MOA or .1 Mil adjustments, Hi-Speed adjustment with windage adjustment capped, separate parallax adjustment with distance markings, digital reticle illumination, enhanced engraving, integrated power throw lever, and XtremeSpeed diopter adjustment. Many of these items are proprietary Nightforce features.

With good ammunition, not delinked bulk FMJ, sub-MOA accuracy is more than obtainable with the AX50. Hornaday .50BMG 750 grain AMAX Match ammunition was used primarily with the AX50. Delinked and FMJ .50BMG was also accessed for initial function testing and zeroing of the Nightforce ATACR optic. Remember the military mainly uses the .50 BMG rifle, whatever specific model it may be, as an anti-material weapon. Yes, rounds on enemy personnel have happened, especially in current theaters of operation in Iraq and Afghanistan, but this is not the primary mission role of the big rifles. The AX50 delivers far better accuracy than merely “minute of engine block” at extended distances with “minute of man” possible at mind blowing distances. The AX50 exceeds previous expectation in terms of accuracy form a shoulder fired .50BMG rifle. AI is not at liberty to name specific clients that deploy the AX50; however, many AX50’s have been sold to NATO forces and are in service around the globe currently.

AX50 is fed from a five round detachable magazine.

The AX50 demonstrated 1 MOA groups at 300 yards and 500 yards at Echo Valley Training Center. Large rounds such as the .50 BMG rounds often exhibit the phenomena of going to “sleep” after traveling some distance down range. For example, accuracy levels at 100 yards are often improved upon at 300 yards or further downrange. For example, a 100 yard group measuring an overall dimension of 2 inches is often followed by a 300 yard group measuring less than 3 inches. One would extrapolate that the 2 inch group at 100 yards to generate a 6 inches group at 300 yards. This phenomenon was not evident during evaluation with the AX50 either due to the ammunition used or the rifle itself. 100 yard groups were in the sub-1 inch range for three rounds with the size of the .50BMG producing only a jagged hole on the target.

AI does not advertise specific accuracy standards for the AX50 due to ammunition being such an important part of the equation. However, AX50 rifles competed headed to head with full blown custom rifles at .50Cal National Championships last year. Remember the AX50 is an off the shelf military grade sniper system, not a custom match rifle, yet it competed at this level more than holding its own. Interestingly, Hornady Ammunition was used in this format as well due to the obvious emphasis on accuracy at the match.

Recoil was surprisingly manageable from the bolt action AX50. While muzzle blast was impressive as expected, the shoulder and face was spared from discomfort. This is a compliment to the AX50’s ergonomics, muzzle brake, and overall design. Firing from supported field positions is not an issue with the AX50. The effective management of recoil translates into a user being more comfortable settling in behind the big AX50 and sending accurate rounds downrange. The Accuracy International AX50 takes a back seat to no rifle in terms of downrange interdiction power and repeatable accuracy.

Muzzle blast is as expected with the AX50, however recoil was not intolerable with even smaller framed shooters not intimidated.


Accuracy International

Nightforce Optics

Echo Valley Training Center


Muzzle blast is as expected with the AX50, however recoil was not intolerable with even smaller framed shooters not intimidated.
The balance and recoil control of the AX50 allowed for field expedient firing positions.