The M24 SWS was mainstay of the US Army for over 30 years, starting in the 1980s, and proved itself an excellent platform for the mission it was designed for. It was big, it was heavy, it was accurate, and it was combat proven. But it was designed for a different war than what the USA found itself in in after the turn of the century. Early on in the Global War on Terror (GWOT) the Army found itself fighting unconventional battles in urban environments in Iraq where the ranges of the .308 were adequate, but the close and hot engagements required more firepower to be on hand. As such, the M110 Semi-Auto Sniper System (SASS) was adopted as a sniper rifle to supplement, and in some cases, replace the M24. As the GWOT further progressed to the much more rural and wide-open battlefields found in Afghanistan, the demands and requirements for a sniper rifle changed again. This time, a rifle with superior long range capabilities was needed and not the rapid engagement abilities of the M110.

But the war was still very hot and there was not an extended amount of time for which to procure a new weapon system and cartridge. Here is where the foresight of the original designers of the M24 paid off. One of the odd features of the M24 was that it was a Remington Long Action whereas only a short action was needed for the 7.62x51mm NATO cartridge. So the bolt stroke on the M24 was extra long and this did cause some issues from time to time. But what the long action bought the army, was the ability to upgrade the M24 in the future from the .308 to a long action cartridge, which was intended to be the .300 Win Mag. Back in the 1980’s when the M24 was developed, the .338 Lapua was a new concept, the .300 Norma was not even a pipe dream and the .300 Win Mag was a solid long range cartridge.

[M24 from the Sniper Central Collection]

Rightfully so, the first option the Army turned to when they needed more range than their M24’s could deliver, was to upgrade the M24 and chamber it in .300 Win Mag, and that is what they set out to do. The Army also set out to not only improve the range of the rifle, but they wanted to add a fully adjustable stock, make the rifle capable of mounting a suppressor, and also incorporate a detachable box magazine. These were all things the M24 did not have. They also decided to forgo the need to accommodate auxiliary sights.

Sniper Central Ballistic Cards

The contract was once again awarded to Remington who was the manufacturer of the original M24 SWS and 250 prototypes of the new rifle were ordered, designated the XM2010. The nomenclature referenced the expected year of deployment, 2010.

To achieve the desired results, a folding chassis system was selected that housed a 5 round DBM. The folding feature helped keep the length down when being transported. The barrels were made by Obermeyer and featured 5-R rifling, made popular by the original M24. The barrel was 24″ long, heavy profile, and was hammer forged and of course, it was free floated.

As can be seen in the picture above, there are numerous picatinny style rails attached to the chassis to allow for attaching various accessories. There is also a monolithic rail along the top making it easier for mounting forward mounting night vision to augment the day optic sight (DOS).

To compliment the rifle, a new DOS also needed to be selected and again, relying on experience obtained with the M24, the Army turned to Leupold Optics. Because of the longer range capability of the new rifle, and with the advancement in optics over the previous three decades, the choice was for a higher powered variable zoom optic. The chosen scope was the Leupold Mk6 6.5–20×50mm ER/T M5A2. This scope featured a 34mm tube, which allowed for more vertical adjustment range, as well as their M5 knobs calibrated in MIL. The reticle choice was the Horus H-58 which is a popular Christmas Tree style reticle.

The ESR, or Enhance Sniper Rifle, were fielded with a AAC muzzlebrake that allowed the fitting of the quick detachable AAC suppressor. The rifles also were fielded with either the AN/PVS-29 or AN/PVS-30 clip on night vision devices.

The required accuracy for these rifles was 1 MOA with A-191 .300 Win Mag ammo. The A-191 used the traditional Sierra Match King 190gr HPBT bullet fired at 2900 fps and the declared max effective range was 1200 meters (1312 yards). Each rifle was required to demonstrate 1 MOA before it left the factory.

The 250 prototype XM2010 rifles could not be fielded fast enough and the demand for the new rifles was very high during this busy deployment cycle for the US Army. Even before the prototypes were all delivered the certification and official adoption of the M2010 ESR (without the X designator) happened and the full order of 3600 rifles was placed. But while the intended deployment year was 2010, the rifles actually started being fielded in early 2011.

The rifles were praised by many and the tried and true M24 actions again proved their worth in combat. The special operations community were the first to receive the rifles and then they started to make their way to the regular line units with a priority given to units deploying to combat. Eventually a total of 2558 M2010s were built and deployed through 2014. We are not sure why the full compliment of 3600 were not completed, but we suspect the demand for the .300 tapered off with the slowing down of combat operations. The Advanced Sniper Rifle (ASR) and Precision Sniper Rifle (PSR) programs had also officially begun for SOCOM and the Army was watching this development for the adoption of an all new sniper rifle.

M2010 in action in the Kunar province, Afghanistan.

In 2021 the US Army did announce the adoption of the Mk22 PSR as their new standard sniper rifle and the process to replace the M2010 began then. The M2010 had a fairly short life span for a small arms weapon in a modern military, it only lasted about 10 years. During that period the rifle did not go through many modifications and it stayed relatively the same.

The one big change that actually did provide additional capability for the M2010 was the development of a new load for the .300 Win Mag. This was known as the Mk248Mod1 and it used the 220gr Sierra Match King Bullet launched at 2850 fps. This new load extended the max effective range of the rifle to 1370 Meters (Conveniently 1500 yards). You can read more about the development of that load on our 300 WM History Page.

The M2010 can be considered a stop gap rifle that was pressed into development due to a need for a rifle with more capability than the M24. In that role it served very well and provided the needed ability to engage targets beyond 1500 yards, which they did on a number of occasions. It was a rifle that was forged in combat, proven in combat, and is being retired while still in combat.

Those that used them tend to have a favorable opinion of the rifles. They did what they needed to do and some are still in use today as the fielding of the Mk22 is slated to take a few more years still. With the retirement of the M2010 we not only close the chapter on the ESR, but we are also closing a much longer chapter on the M24 SWS, a legend in its own right.

Sniper Central


Edward Wezain

It will be interesting t see if these rifles are refurbished and sent to Ukraine.


The M2010 Enhanced Sniper Rifle, formerly known as the XM2010 and M24 Reconfigured Sniper Weapon System, is a sniper rifle developed by PEO Soldier for the United States Army.


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