The M110 Semi Automatic Sniper System (M110 SASS) is an American semi-automatic sniper rifle/designated marksman rifle that is chambered for the 7.62×51mm NATO round, developed by U.S. firearm manufacturer Knight's Armament Company. The M110 is to be replaced by the lighter and more compact Heckler & Koch G28.
The M110 Semi-Automatic Sniper System is intended to replace the M24 Sniper Weapon System used by snipers, spotters, designated marksman, or squad advanced marksmen in the United States Army. However, the U.S. Army still acquired M24s from Remington until February 2010. After witnessing the effects of USSOCOM snipers and extensive after-action reports from SOF snipers throughout the Iraqi theater of operations, the U.S. Army ran a competition involving several designs, including rifles from Knight's Armament Company, Remington, and DPMS Panther Arms. On September 28, 2005, the Knight's Armament Co. rifle won the competition and was selected to be the supplier of the M110 Semi-Automatic Sniper System. The XM110 underwent final operational testing in May and June 2007 at Fort Drum, New York by a mix of Special Forces troops and Sniper trained soldiers from the 10th Mountain Division. In April 2008, U.S. Army soldiers from Task Force Fury in Afghanistan were the first in a combat zone to receive the M110. The troops rated the weapon very highly, noting the quality of the weapon and its semi-automatic capabilities compared to the bolt-action M24. The United States Marine Corps will also be adopting the M110 to replace some M39 and all Mk 11 as a complement to the M40A5. It is manufactured by Knight's Armament Company in Titusville, Florida, though the complete system incorporates a Leupold 3.5–10× variable power daytime optic, Harris swivel bipod, AN/PVS-26 or AN/PVS-10 night sight and PALs magazine pouches of yet unpublished origin. The rifle has ambidextrous features such as a double-sided magazine release, safety selector switch, and bolt catch.
The rifle is similar to the SR-25/Mk 11 Mod 0, but differs significantly in buttstock and rail system design. The SR-25, Mk 11 Mod 0, and M110 are based loosely on the original AR-10 developed by Eugene Stoner but feature additional refinements instituted by KAC to maximize parts commonality with the AR-15 design, improve weapon reliability, and increase accuracy.
The main differences between the Mk 11 and M110 are improvements suggested by a user group meeting between NAVSPECWAR, USASOC and USA in 2007:The rail system used: the KAC Free Floated RAS on the Mk 11 is replaced by a URX modular rail system with integral folding front 600-meter back-up iron sight.
The M110 buttstock: fixed, though the buttplate is adjustable for length of pull to match user preferences. Adjustment can be made without tools via a notched hand-tightened knob on the right-hand side of the stock. This feature was added during the change from XM110 to M110. The fixed buttstock also features integral quick-detachable sling swivel sockets located on each side of the stock near the rear of the lower receiver.
The addition of a flash hider to the barrel of the M110, which also necessitates a modified QD Suppressor unit similar to that on the Mk 11.
The M110's use of KAC's one-piece 30 mm scope mount instead of two separate scope rings.
On June 12, 2008, the M110 was ranked #2 on the U.S. Army's top ten inventions of 2007.
According to performance specification (MIL-PRF-32316 (AR) w/AMENDMENT 1, 5 October 2009):
18.104.22.168.1 Accuracy. The distance between the mean point of impact of each shot group, both unsuppressed and suppressed, shall be not greater than 1.1 inches at 300 feet.
22.214.171.124.2 Dispersion. The average mean radius (AMR) (see 6.11), of each shot group shall be not greater than to 0.68 inches at 300 feet. All targets shall be fired on using M118LR ammunition or equivalent, using five (5) round groups.
In April 2011, the U.S. Army issued a request to the private sector to reconfigure or replace the current Knight Armament M110 sniper rifle as the current version of the M110 was not functioning well in the field requiring significant maintenance and replacement of parts. The U.S. Army responded to the referenced article clarifying that the rifle was functioning perfectly and they are just looking for a smaller, lighter version of M110 for the spotter in a sniper team, providing the sniper is equipped with the new XM2010. "The spotter will have an urban sniper support weapon which will be the M110. … Now you’ve increased the lethality of the team…"—Program Manager LTC Chris Lehner.
The specifications the U.S. Army has issued are as follows:
- Operation: Semi-automatic
- Caliber: Compatible with 7.62×51mm NATO cartridges
- Accuracy: Capable of 1.3 minute of angle dispersion or better with match ammunition
- Size: Overall length shall be reduced using a shorter barrel and/or collapsible buttstock. Maximum length not to exceed 39 without suppressor. Desired minimum length is less than 36 with stock collapsed.
- Weight: Weight shall be under 9.0 lb for unloaded rifle without optics and accessories
- Grip: A modular, adjustable pistol grip.
- Trigger: A non-adjustable match style trigger.
- Hand guard: A forend that includes a fixed 12 o’ clock rail with configurable 3, 6, and 9 o’ clock rails.
- Sound suppressor: A muzzle mounted, detachable sound suppressor.
- Muzzle device: A compensator/muzzle brake compatible with the sound suppressor.
- Bipod: Tool-less detachment featuring cant and pan/track capability.
- Day optic: An Army specified variable power day optic and compatible rings.
- Back up sights: Iron sights offset 45 deg from the DOS.
- Sling attachment: Flush cup, quick detach sling attachment points.
- Other: The upgraded M110 must meet the operational and environmental requirements that were fulfilled by the original M110 SASS.
In July 2012, the U.S. Army requested sources to remanufacture the current M110 rifle into the Compact Semi-Automatic Sniper System (CSASS). The CSASS will be a shorter and lighter version of the M110 with a collapsible stock and removable flash suppressor, giving it an overall length of 36 inches (910 mm) and a weight of 9 pounds (4.1 kg) unloaded. The Army wants a capability to convert 125 rifles per month, with the ability to increase to 325 per month. The Army formally requested proposals for the CSASS in June 2014.
On 1 April 2016, the Army announced it had awarded Heckler and Koch a contract with a maximum value of $44.5 million as winner of the competition to replace the KAC M110. The weapon selected was not specified, but was likely the H&K G28; H&K is to produce 3,643 rifles. A goal of the effort was to give snipers a weapon that didn't "stick out" as a sniper rifle; with a suppressor, the M110 is 46.5 in (1,180 mm), 13 in (330 mm) longer than the M4 carbine. A minimum of 30 CSASS units will be used for production qualification testing and operational testing over 24 months. H&K later confirmed that a modified G28 had indeed been selected as the CSASS rifle. The G28 is nearly 6 cm (2.5 in) shorter and 1.3 kg (3 lb) lighter than the M110 (unloaded and without a suppressor) and will cost about $12,000 per rifle.
In 2009, the M110 rifle and commercial equivalents were added to the list of NRA-legal US service rifles under rule 3.1.6 of the NRA High Power Rifle Rules. Argentina: Used by GEOF (Argentine Federal Police).
Armenia: Used by Army Special Forces.
Colombia Used by Colombian Army.
Iraq: Used primarily by ISOF snipers.
United States: Used primarily by US Army snipers.
Mexico: Used primarily by Mexican Special Operations Forces snipers.
Poland: Used by Polish Special Forces.
Turkey: Used by Army Special Forces