This results in less barrel fouling, and more consistent point of impact, compared to conventional rifling when relatively high numbers of rounds are fired between cleaning, as might be expected in military applications.

The actual rifle requirements for accuracy were .35 MOA from a machine rest and according to Major John Mende (ret.

The A2 model features a detachable 5-round magazine, top-mounted and adjustable side-mounted Picatinny rails (advertised by Remington as "MARS", or Modular Accessory Rail System), barrel modifications designed to accommodate a sound suppressor, and an improved H-S Precision PST-026 stock with adjustable cheek height and length of pull.

Remington developed the M24A3 SWS, a variant of the M24 chambered for the .338 Lapua Magnum round (8.58×70mm) and feeding from a 5-round detachable box magazine.

It can also use detachable front and rear Back-Up Iron Sights in an emergency (BUIS units are standard accessories that can be fitted to the Picatinny Rail that runs on the top of the receiver and along the barrel).

The U.S. Army put out a solicitation in May 2009 for reconfiguring M24 Sniper Weapon Systems currently available in Army inventory consisting of a:[11] The US government purchased MK 248 MOD 1 .300 Winchester Magnum match-grade ammunition in 2009 for use in .300 Winchester Magnum sniper rifles like the U.S. Navy Mk.13 MOD 5 rifle or reconfigured M24 SWSs.

According to the U.S. Navy, this ammunition should increase the maximum effective range of .300 Winchester Magnum sniper rifle systems to 1,370 m (1,500 yd), decrease wind deflection on bullets in flight and use a reduced muzzle flash propellant that remains temperature stable across an operational temperature range of −32 to 74 °C (−26 to 165 °F).

[12][13][14] In September 2010, the United States Army's Joint Munitions and Lethality Contracting Center awarded Remington a Firm Fixed Price Indefinite Delivery/Indefinite Quantity contract (W15QKN-10-R-0403) for the upgrade of up to 3,600 M24 Sniper Weapon Systems currently fielded to the Army pending type classification as the M24E1 Enhanced Sniper Rifle (ESR).

The major configuration change for this system is the conversion from 7.62×51mm NATO to dimensionally larger .300 Winchester Magnum ammunition exploiting the M24's "long action" bolt to provide additional precision and range.

[16][17] The M24E1/XM2010 is considered a "total conversion upgrade", by which the barrel, stock, magazines, muzzle brake, suppressor, and even the optics will be changed.

Besides the rechambering and rebarreling with a 610 mm (24 in) long, 254 mm (1 in 10 inch) twist rate (5R) hammer-forged barrel the main reconfiguration changes compared to 7.62×51mm NATO chambered M24 rifles are:[18] According to Remington Arms, each rifle is tested to meet (and typically exceeds) the requirement to fire ≤ 1 MOA (less than a 2-inch shot group at 200 yards) before being released for fielding.

[16] Based on the results and feedback from troops, the U.S. Army decided in May 2011 to replace its entire fleet of M24s, ordering a total of 2,558 M2010 Enhanced Sniper Rifles.

The M2010 achieved Type Classification-Standard in July 2013 and Full Materiel Release in September 2013, supporting procurement for the balance of the Army requirement.

[21][22][7] In 2019, the Israel Defense Forces started to upgrade the M24 and replace the stock and receiver of the old M24 rifles with a modern MDT Defense M24 Chassis stock assembly with AR15/M16 pistol grip that increases the number of physical adjustments to individual ergonomic preferences, magazine feeding and an M-LOK forend with attachable MIL-STD-1913 Picatinny rails around the barrel.