Performance Specification
SOF Combat Assault Rifle Heavy
27 February 2004
1. SCOPE
1.1. Scope. This specification covers the requirements of the SOF Combat Assault Rifle Heavy (SCAR H), 7.62X51mm assault rifle. It is the intent of the SOF Combat Assault Rifle (SCAR) program to procure for the United States Special Operations Command (USSOCOM) the most reliable, rugged, accurate, safe and ergonomic weapons available.
Classification types. The SCAR Modular/Family of Weapons will share ergonomic commonality and the highest degree of parts commonality possible.
1.2.1 SCAR Heavy. The SCAR H shall possess the ability for caliber modularity (open architecture platform), while still demonstrating an optimized design for the baseline caliber of 7.62x51mm (alternate calibers are known to be 7.62x39mm). Future enhanced calibers will also be considered. Modular options in the baseline caliber include a CQC, Standard, and Sniper Variant (SV).
2. APPLICABLE DOCUMENTS
2.1 General. The documents listed in this section are specified in sections 3, 4, and 5 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in section 3, 4, or 5 of this specification whether or not they are listed.
2.2 Government Documents.
2.2.1 Specifications and standards. The following specifications and standards form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents shall be those listed in the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation.
Standards, Military:
Federal Standard 595B Colors Used In Government Procurement
PS/4081/C03/1337 SOF Combat Assault Rifle (SCAR) Light Performance Specification
PS/4081/C03/1342 Enhanced Grenade Launcher Module (EGLM) Performance Specification
MIL-STD-810F Environmental Test Methods and Engineering Guidelines
MIL-STD-1913 Dimensioning of Accessory Mounting Rail For Small Arms Weapons
TOP 1-2-608 Sound Level Measurements, dated 17 July 1981
ITOP 4-2-602 Rough Handling Tests
TOP 3-2-045 Automatic Weapons, Machineguns, and Hand and Shoulder Fired Weapons.
TOP 3-2-504 Safety Evaluation of Hand and Shoulder Weapons
MIL-C-46931F Cartridge, 7.62MM Ball M80
MIL-C-46281F Cartridge, 7.62MM Tracer M62
MIL-C-46933A Cartridge, 7.62MM Blank M82
MIL-C-46477B Cartridge, 7.62MM High Pressure Test M60
MIL-C-46933A Cartridge, 7.62MM AP M993
DTL 8597557 Cartridge, 7.62MM Special Ball LR M118LR
2.3 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. Copies of military specifications and standards are available from: Standardization Document Order Desk, 700 Robbins Ave., Bldg #4, Section D, Philadelphia, PA 19111-5094.
Note: From this point on, the term SCAR H encompasses all three variants (CQC, S, and SV).
3. REQUIREMENTS.
NOTE: Thresholds and Objectives. Section 3, designates threshold requirements and objectives. All Threshold requirements are earmarked with a (T). All shalls designate a threshold requirement. All Objectives are earmarked with a (O). All shoulds designate an objective.
3.1 SCAR major components. The SCAR H shall include a rifle with the following ancillary equipment: sling, vertical forward handgrip, Blank Firing Adapter (BFA), bipod, cleaning kit, operators manual, and ten magazines (T). The SCAR H (SV) shall be provided with a required sound suppressor (see paragraphs 3.2.2.6 and 3.2.2.6.1) (T).
3.2 Performance requirements.
3.2.1 Physical description.
3.2.1.1 Size/weight. The SCAR H (S) rifle shall have a stock that is collapsible or foldable to an overall system length of 40.2 extended and 30.3 collapsed/folded (T), or less (O). Without magazine it shall weigh no more than 9.0lbs unloaded (T), less than 8.0 lbs unloaded (O).
3.2.1.2 Stock. The SCAR H (S, CQC) shall have a multi-position (more than two) collapsible or folding stock to facilitate quick entry and exit from tactical vehicles and use with body armor (T). The weapon shall be able to operate and fire, to include access to the charging handle, when the stock is in any position (T). The SCAR H (SV) should have a fixed stock with an adjustable length of pull and an adjustable cheek piece (O).
3.2.1.3 Ammunition magazines. The SCAR H shall utilize a 7.62X51mm 20 round magazine that is rugged and reliable supporting reliability requirements of paragraph 3.2.3.10 and the rough handling requirements of 3.2.3.14 of this specification (T). SCAR H (SV) shall have a 10 round 7.62x51mm magazine (T). SCAR H in 7.62x39mm shall use AK/AKM style magazines (T). The SCAR should be capable of accepting an external magazine carrier with extra magazine stowed in close proximity to the magazine well (O). SCAR H magazines shall have tactile signatures when objective calibers other than 7.62x51mm are used (T).
3.2.1.4 Sling mounts. The SCAR H shall have sling attachment points that facilitate mounting to a one, two or three point sling to the left or right (T). The sling mounts shall not interfere with accessories/SOPMOD items, shouldering, aiming, and acquiring sight picture both day/night (T). The sling mounts should be integral with the weapon (O).
3.2.1.5 Surface finish. All external and visible SCAR H surfaces shall be of a rough, dull, non-reflective coating/finish that retains paint (T). The SCAR H and components shall be delivered in Color # 3 0118 Fed Std 595B (T). The SCAR should be in a type of finish to support various camouflage combinations with minimum infrared/radar signatures (O). Finish shall be resistant to peeling, flaking, chipping, and require a minimum of operator preventative maintenance (T). Internal Coatings should be lubricious, mitigating the use of lubricants (O). Non-metallic components shall be fungus and chemical resistant (T).
3.2.1.6 Weapons internal storage. The SCAR H should have an integral, permanently affixed waterproof storage compartment capable of storing spare batteries, cleaning kit items, etc. (O), should be waterproof to 66 feet for 2 hours (O).
3.2.1.7 Weapon controls.
3.2.1.7.1 Trigger pull. Trigger shall release the sear to fire the weapon with a consistent amount of pressure, at 4.5 to 6.5 pounds pull with minimal creep (T). Weight of trigger pull, within accepted range, shall be consistent during weapon operation (T). Trigger shall reset after being released, even if the weapon is not fired (T). The hammer/firing pin/striker shall not be released when exposed to harsh/rough-handling conditions to maintain safe handling of the weapons (T),
3.2.1.7.2 Magazine release. The SCAR H shall have a magazine release capable of single-handed use (left or right hand) without releasing the firing grip (T). The SCAR H should be designed so that the magazine loads into the receiver forward of the firing grip (O). Upon activating magazine release, the empty magazine shall drop free of the weapon (T).
3.2.1.7.3 Bolt hold-open. The bolt shall remain open after ejection of the last round from the magazine (T). The bolt release will be operable, using the left or right hand (T).
3.2.1.7.4 Charging handle. The SCAR H shall have a charging handle capable of being operated by the left or right hand (actuated when weapon is on the left or right shoulder of the operator) (T) and shall be fully operable with stock in any position (T).
3.2.1.7.5 Safety/selector switch. The SCAR shall have a safety/mode selector that rotates through 3 positions of semi-automatic, automatic, and safe (T). The SCAR H shall have a safety mechanism that prevents the weapon from firing when the trigger is depressed and the safety/selector is "on" safe (T). The safety shall be capable of being manipulated by left or right hand use, easy to operate under all environmental conditions and operator dress, and shall be capable of ready status verification (on/off) by both sight and touch (T). Manipulation to full-auto mode shall be deliberate and not exceed 900 from safe (T). The SCAR H shall have a redundant mechanical safety mechanism that prevents firing until intentionally initiated by the operator (T). The SCAR H shall have a selector that provides tactile signature to the operator with minimal audible signature when utilized (T). The SCAR H should have a selector that has no audible signature when utilized (O).
3.2.1.7.6 Iron sights. Iron sights shall not interfere with other weapon, or SOPMOD components (T). Compatible front and rear iron sights, either flip-up or low-profile-fixed, are required (T). Once zero is set, sights shall maintain position until intentionally changed by the Operator (T). The minimum distance between the front sight post and the rear sight aperture is 10 inches (T). The sights shall be adjustable for windage and elevation in 1 MOA increments, and be capable of adjustment to ranges out to 600m (T). The adjustments should be tactile and should not require the use of tools (O). With modular barrel changes, front and rear sight shall accommodate battle sight zero for specific barrel in use (T). Vendor shall provide instructions to accomplish 300 meter zero at 25 and 10 meters in operators manual using both M118LR and M80 Ball (T).
3.2.1.8 Workmanship. Workmanship and finish shall be in accordance with the best commercial practice (T). Finished weapons and parts shall not exhibit poor material and processing such as seams, laps, laminations, cracks, visible steps, sharp edges, nicks, scratches, burrs, deformations and missing operations which may affect serviceability, functioning, operation, appearance or safety (T). Flashing or other extraneous metal shall be removed from cast or forged parts (T). Hammering to shape, salvage operations (including repair by welding except that normal cosmetic welding or surface blemishes on forgings or castings prior to heat treatment shall be permissible except on the barrel) or other similar practices shall not be permitted without prior approval from the contracting officer.
3.2.1.9 Identification markings. The SCAR H shall display identification markings addressing weapon nomenclature and caliber, manufacturer, and serial number (T). The SCAR H shall have an area designated for automated identification markings to facilitate accountability and maintenance scheduling (T). Identification should be accessible without removing the weapon from its rack (O). Identification markings shall be engraved, cast, or stamped (impressed) on the receiver in a manner easy to read and identify, not susceptible of being readily obliterated, altered, or removed (T). In the case of polymer weapons, this data shall be placed on a permanent metal surface (e.g., onto a metal plate inserted in the receiver during the molding procedure) (T).
3.2.2 Design requirements.
3.2.2.1 Modularity: The SCAR H shall be adaptable to three separate barrel lengths for varying mission requirements (T). The standard barrel shall have the length necessary to accurately engage targets to 600 meters, while maximizing terminal effects (T). The CQC barrel shall be effective engaging targets to 200 meters while maximizing terminal effects (T). The Sniper Variant (SV) shall have a barrel length optimized to accurately engage targets to 800 meters and beyond while maximizing terminal effects (T). Barrel length change shall be accomplished either by upper receiver or barrel change at the unit level (T), by the operator (O), with tools as necessary. Barrel modularity shall be accomplished in such a way as to meet 7.62mm headspace requirements without operator adjustment or measurement (T). Barrel modularity shall be accomplished in such a way as to meet bore sight and zero requirements with minimal operator adjustment /measurement (T). The SCAR H barrel shall be mounted in such a way that accessory mounting causes no point of impact shift (T). Barrel/module change shall be accomplished within 20 minutes (T), 5minutes (O). The SCAR H shall display open architecture to provide the platform for caliber modularity (T).
3.2.2.2 Field stripping. The SCAR H shall be capable of quick and easy field stripping without the use of tools for normal care and cleaning in the field (T). Field stripping shall provide access to the barrel, bolt, chamber, and operating mechanism (T). The weapon shall be incapable of improper assembly at the fieldstrip level to the detriment of functioning or safety (T). All field-strippable takedown pins shall be captive (T). Field stripping of the SCAR H shall be compatible with combat clothing (including MOPP IV and cold weather gear, both day and night) (T).
3.2.2.3 Parts interchangeability. All component parts or inseparable subassemblies shall be 100% interchangeable between weapons without hand or machine fitting (T). Interchange of parts shall not adversely affect functioning, reliability or accuracy of the weapon (T).
3.2.2.4 Commonality of SCAR systems. SCAR weapons, Light and Heavy, shall maximize ergonomic and parts commonality (T). SCAR H and SCAR L should be the same weapon with exception for size and caliber (O).
3.2.2.5 SOPMOD compatibility / interoperability. The SCAR H shall have a rigid MIL-STD-1913 rail at the 12:00 position running continuously from the rear sight to the front sight, which may be mounted to the upper receiver or integral to the weapon (T). The 12:00 rail shall number the slots in alternate even numbers running the extent of the rail from back sight to front (T). The SCAR H shall also have additional MIL-STD 1913 rails at 3:00, 6:00, and 9:00 in the fore-arm/hand guard area (T). All rails shall be capable of maintaining the bore sight alignment (T). The MIL-STD 1913 rails shall be mounted to the weapon to maximize; rigidity (no loss of zero due to rough handling), independence from the barrel (no interference with the natural harmonic vibrations of the barrel during firing), and provision for mounting future 6:00 subsystems more closely to the gun barrel (decrease in offset between the 6:00 subsystems and the axis of the bore) (T). SOPMOD/MWS items mounted on rail system shall not be blocked or interfered with by other SCAR components/features (T). The SCAR H shall be compatible with the Enhanced Grenade Launcher Module (EGLM) (T). SCAR H in any barrel length configuration shall mount the EGLM 40mm grenade launcher on 6:00 position (T). The rail interface shall be capable of withstanding the recoil forces generated by firing the 40mm grenade launchers with a cartridge producing a pressure of 230 bar (T). The SCAR H rails shall exhibit no detectable shift in zero, when the EGLM 40mm weapon is fitted to the SCAR H, and during firing of the EGLM (T). The SCAR H EGLM interface shall be sufficiently robust so as to suffer no damage through firing 1600 rounds of 40mm grenade ammunition (T).
| BLOCK I Original Subsystems | |
| Grenade Launcher Leaf Sight | 1010-01-418-4588 |
| 4x Day Optical Scope | 1240-01-412-6608 |
| Reflex Sight CQB | 1240-01-435-1916 |
| AN/PEQ-2 Infrared Illuminator | 5855-01-422-5253 |
| AN/PVS-17A Mini Night Vision Sight | 5855-01-474-8904 |
| Universal Pocketscope Mount (for AN/PVS14) | 5855-01-482-6164 |
| Universal Pocketscope Mount (for AN/PVS18) | 5855-01-485-7749 |
| Universal Pocketscope Mount (for M68 CCOS and ECOS-N) | 5855-01-485-7755 |
| AN/PEQ-5 Carbine Visible Laser | 5860-01-439-5409 |
| BLOCK I Phased-Replacement Subsystems | |
| Visible Bright Light II (VBL II) | 5855-LL-L99-7589 |
| Enhanced Combat Optical Sight-Navy (ECOS-N) | 1240-01-495-1385 |
Muzzle brake and sound suppressor. The SCAR H shall interface with a compatible sound suppressor/muzzle brake-flash suppressor (T). All SCAR H variants should utilize the same sound suppressor (O).
3.2.2.6.1 SCAR H sound suppressor. SCAR H function/reliability/accuracy shall not be degraded by the installation of a sound suppressor (T). The SCAR H sound suppressor /attachments shall be made in such a way as to preclude the use of the SOPMOD 5.56mm suppressor on the SCAR H (T). The SCAR H suppressor shall lower the average peak sound pressure level 25dB (T), 28dB or more (O) and shall not degrade system accuracy by more than .5 MOA (T), 0.0 MOA (O), nor have a unpredictable shift of impact (unsuppressed versus suppressed) of greater than 2.5 MOA (T), 1.0 MOA (O), when attached. The SCAR H suppressor/attachment system shall have a minimum functional service life of 10,000 rounds (T), 30,000 rounds (O). Suppressor shall attach/detach under all conditions without the use of tools (T). The suppressor shall withstand, with no loss of performance, 100 rounds are fired in the full automatic mode (T). All environmental and performance requirements in this document shall apply to the SCAR H suppressor.
3.2.2.7 Corrosion control. The coating materials shall protect the SCAR H from degradation in all SOF climatic environments and weather conditions experienced in all climates and geographical areas including maritime, coastal, desert, tropical jungle, arctic, urban areas, and mountain environments (T). The materials and coatings shall minimize the attraction of dust and contamination (T). Parts are to be corrosion resistant (T), corrosion proof (O). The SCAR H shall be protected with a durable corrosion resistant coating (T), corrosion proof coating (O), constructed of corrosion resistant materials (T), which is/are abrasion, impact, and battlefield chemical resistant in the NBC environment (T). SCAR H shall exhibit no functional degradation after salt fog exposure 4-day (T), 10 day (O).
3.2.2.8 Fungus. The SCAR H should be constructed of materials that are inert to fungus, or that are fungus resistant (O).
3.2.2.9 Static load. The SCAR H shall withstand a static load of 246 pounds for 60 seconds with no permanent physical distortion/damage that effects performance (T).
3.2.3 Performance characteristics.
3.2.3.1 Caliber, chamber and headspace. SCAR H shall be chambered for 7.62X51mm NATO ammunition (T). SCAR H shall reliably function with the types of ammunition found in paragraph 2.2.1 (T). After proof firing, headspace shall not be less than 1.633 inches or more than 1.6380 inches when measured to the .400 inch datum diameter on the first shoulder of the chamber (T).
2. Non-catastrophic failure. The SCAR H shall not fail in a catastrophic manner when subjected to extremes in operational and environmental employment, or due to over stressing system during high operational use (T). Catastrophic manner is defined as the SCAR H failing in such a manner as to become a hazard to the operator or friendly force in the immediate vicinity. Failure inducing conditions may include but are not limited to: bore obstruction (including water), overheating, and environmental extremes.
3.2.3.3 High weapon temperature operation. Under severe firing schedules (200rds in 5 min.), the operator should be able to operate the weapon while grasping the hand guard without injury from burns (O).
3.2.3.4 Cartridge ejection. The SCAR H shall eject expended cartridges away from other shooters in parallel or on-line as well as the face and body of left-handed operators (T). The SCAR H should have an available brass catcher for the enhancement of platform based shooting and clandestine operations (O).
3.2.3.5 Sustained rate of fire. The SCAR H shall achieve a sustained rate of fire of 25rds per minute (T), 50rds per minute (O).
3.2.3.6 Barrel life. The SCAR H shall have a functional and effective Barrel Life of 15,000rds (T), 35,000rds (O).
3.2.3.7 System service life. The SCAR H shall have a fully functional service life without overhaul for a minimum of 15,000rds (T), 90,000rds before overhaul (O).
3.2.3.8 Noise emissions. The SCAR H shall be designed to minimize potentially hazardous noise emissions experienced by the operator (T). The SCAR H unsuppressed should not exceed dB emission levels of current equivalent systems (O).
3.2.3.9 Cook-off characteristics. The SCAR H shall not cook-off after firing 180 rounds at 70 degrees F (T), 180 rounds or greater at 125 degrees F (O) using fully automatic fire, continuous bursts, with no cooling time between magazine changes.
3.2.3.10 Reliability. The SCAR H, while following the appropriate maintenance schedule shall have a minimum Class I Mean Round Between Failures (MRBF) as listed in the below table (T).
| Failure Class | MRBF | Maximum allowable Failures permitted in 16,000 Rounds |
| I (MRBF) | 2,000 | 8 |
| II (MRBF) | 8,000 | 2 |
| III (MRBF) | 15,000 | 1 * |
* No broken parts causing weapon to cease function.
Failure Classification:
Class I: A failure that may be immediately clearable by the operator within 10 seconds or less while following prescribed immediate action procedures.
Class II: A failure that may be operator clearable requiring more than 10 seconds but not more than 10 minutes. Only the equipment and tools issued with the weapon may be used to clear the weapon.
Class III: A failure of a severe nature. The failure; (1) is operator correctable but requires more than 10 minutes, (2) operator cannot correct and requires assistance (no time limit), or (3) requires higher level of maintenance, or authorized operator correction cannot be accomplished because of unavailability of necessary tools, equipment or parts.
Failure Scoring. The maximum number of failures permissible is eight (8). These failures may be in any combination of class II, III, or I up to the maximum permitted as indicated in the table above. A part determined to be unserviceable during the scheduled maintenance, shall be replaced and not scored as a reliability failure. However, for each weapon, more than one change of the same part shall result in failure of the reliability test. Failure to meet the barrel/receiver life requirements shall result in failure of the reliability test. Receivers or barrels becoming unserviceable after meeting their life requirements shall not be considered as chargeable failures. Unserviceable parts discovered after the reliability firing is completed shall not be scored as a reliability failure.
3.2.3.11 Accuracy. Ammunition used in the precision and targeting paragraphs will be M118LR.
3.2.3.11.1 Precision. The SCAR H (S & SV) shall not increase dispersion by more than 1.0 MOA measured at 300m (T), .25 MOA measured at 300m (O) to baseline ammunition performance. The SCAR H (CQC) shall not increase dispersion by more than 1.0 MOA at 100m (T), .25 MOA at 100m (O) to baseline ammunition performance.
3.2.3.11.2 Targeting. The iron sights shall be capable of being adjusted to provide point of aim point of impact at 600 meters (T).
3.2.3.11.3 Probability of hit - semi-automatic fire. Using M118LR 7.62X51mm ammunition, the SCAR H (S) shall enable the operator to engage targets up to 300m for point targets (E-type silhouette) /500m for area targets (3x5) with a 70% hit ratio firing 20 rounds within 2 minutes using iron sights (T). SCAR H (CQC) shall engage point targets at 200 meters with a 70% hit ratio firing 20 rounds in 2 minutes using any sight (T). The SCAR H (SV) shall engage at 600m for point targets (E-type silhouette) /800m for area targets (3x5) using optics (T), 800 meters for point targets/1000 meters for area targets using optics (O).
3.2.3.11.4 Automatic firing accuracy. The SCAR H (S) shall be able to achieve 2 hits using 5 round burst, 75% of the time from the prone position on a standard silhouette target at a range of 50 meters (T), 100 meters (O). Test shall be conducted using M80 ball 7.62mm ammunition, iron sights, with daylight conditions with minimum to no crosswinds.
3.2.3.12 Proof firing. Each SCAR H shall be capable of withstanding the firing of a Government standard MIL-C-46477B Cartridge, 7.62mm High Pressure Test M60 and marked accordingly (T). Each high-pressure component shall be inspected for evidence of cracks/failure using magnetic particle processes.
3.2.3.14 Rough handling. When dropped from a minimum height of 1.5 meters (5 feet) as described in TOP 3-2-045 and ITOP 4-2-602, the SCAR H shall be capable of withstanding the impact without causing any structural or functional damage to the weapon and capable of withstanding the shock without firing a primed empty cartridge (T). The SCAR H shall be tested with and without a sound suppressor attached. The SCAR H shall withstand vibration and rough-handling requirements as defined by MIL-STD-810F, Method 514.5 (T).
3.2.4 Operational environmental requirements.
3.2.4.1 Environmental requirements. The SCAR H with suppressor shall operate effectively, without damage or degradation of performance, in all climates and geographical areas that include sand, swamp, tundra, grasslands, forest, jungle, urban areas, maritime, riverine, and mountainous environments (T). The SCAR H shall also operate at high and low temperature extremes (-40 degrees F to 140 degrees F) as well as other hostile (ice/rain/sand/dust/dirt/ mud/surf/salt fog) environmental conditions (T). The SCAR H shall operate at altitudes ranging from sea level to 12,000 feet (T).
3.2.4.2 Airborne operations. Operators shall be capable of using the SCAR H following static lines and military free fall insertions (T).
3.2.4.3 Over the beach capability.
3.2.4.3.1 Drain time. The SCAR H requires a two second drain time to fire out of the water with no special manipulation of the weapon required other than firing mode selection (T). Zero drain time to fire with no special manipulation of the weapon other than firing mode selection (O). Zero drain time capable with sound suppressor (O).
3.2.4.3.2 Surf zone operations. The SCAR H shall be able to fire repeatedly (out of water/submerged/out of water) in full and semi automatic modes of fire for up to 90 rounds without catastrophic weapons failure, or weapon reliability compromised to any degree (T).
3.2.4.3.3 Saltwater immersion. The SCAR H shall be capable of being submerged in salt and fresh water to a depth of 66ft. for a minimum of 2 hours without operational degradation (T), 8 hours without operational degradation (O).
3.2.4.4 Nuclear, biological, chemical (NBC) operations. The SCAR H shall reliably function when exposed to NBC environments (T). Weapon shall suffer no functional degradation from decontamination procedures (T).
3.2.4.5 Operational suitability/effectiveness. Acceptance shall be based on the ability of the SCAR H system to meet all stated threshold and expressed objective requirements as well as Operators (subjective and objective) determination of operational suitability, effectiveness and ergonomic acceptability. Factors include but are not limited to increased live-fire hit scores, decreased live-fire engagement times, improved speed/accuracy of engagement and function, controllability in semi-automatic and full-automatic fire, improved handling qualities, ease of operation, weight, and snag free movement through vegetation and battlefield obstacles. The SCAR H shall be highly portable, lethal, durable, and easily maintainable in the field (T). It shall be usable by right or left-handed operators (T). The weapon shall be operable by personnel wearing anti-contact protection (cold weather, scuba, or Chemical, Biological, Radiological gloves) (T). The weapon shall not present any sharp edges or pinch points that could damage the clothing or protective equipment of the soldier or injure the soldier (T). The SCAR H design shall allow the Operator to immediately clear a malfunction without the use of special tools (T). Examples of weapon malfunction are, but not limited too, jam, hang-fire, and failure to extract or feed. Once cleared, the weapon shall resume operation without the use of special tools or without exposing the Operator to increased risk during a combat engagement (T).
3.2.5 Ancillary equipment.
3.2.5.1 Sling. The SCAR H shall have a detachable, adjustable, ambidextrous sling, designed for load bearing for extended duration, and insulated from, or resistant to, excessive barrel temperature (T). The sling shall not interfere with accessories, shouldering, aiming, and acquiring sight picture both day/night (T).
3.2.5.2 Bipod. The SCAR H shall have a detachable bipod with a locking feature to prevent inadvertent collapsing of the bipod legs (T). When in the stowed position, bipod shall be foldable with the right or left hand and not interfere with mounted accessories (at 3, 6, 9 and 12 oclock positions) without EGLM (T), with EGLM (O). The bipod shall have independently adjustable legs (to accommodate irregular terrain) (T). The bipod will present a minimal snag hazard (T). The feet shall be configured to accommodate surfaces such as ice, sand, mud, earth, concrete, etc (T). The weight of the bipod shall not exceed 1 lb (T), 10 oz (O).
3.2.5.3 Handgrip. The SCAR H shall have the capability for installation of a detachable vertical forward handgrip (T). Grip shall be constructed to resist breakage (ex: during CQC strikes) (T). Grip shall attach to 6:00 rail at any point and positively secure with without the use of tools (T). Grip shall not vibrate loose during sustained fire or other SOF mission profiles (T). Grip should provide flush interface for accessory actuation switches (O). Grip should provide a waterproof storage compartment capable of holding spare batteries etc. (O).
3.2.5.4 Blank firing capability. The SCAR H shall be provided with a blank cartridge firing adapter that allows the weapon to function reliably (T), for all barrel lengths and calibers (T), a blank firing barrel (BFB) (O). The SCAR H should be provided with a blank cartridge firing capability that prevents chambering or firing of multiple live rounds (O), and prevents insertion of standard magazine (O). SCAR H when blank adapted, shall function reliably through 140 rounds without adjustment (T).
3.2.5.5 Cleaning kit. The SCAR H shall be equipped with a compact cleaning kit for general field maintenance and cleaning (T).
3.2.5.6 Jump bag compatibility. The SCAR shall be compatible with the current in M1950 Adjustable Individual Weapons Case (Parachutists), NSN: 8465-01-109-0702. (T).
4.0 Verification.
4.1 System definition. The SCAR system will be inspected for conformance to the system description in paragraph 3.1.
4.2 Performance.
4.2.1 Physical description.
4.2.1.1 Size/weight. Measure and weigh SCAR H to determine compliance with requirement of paragraph 3.2.1.1.
4.2.1.2 Stock. Verify that the stock collapses or folds, or both. Measure the degree of adjustment available, both vertically and lengthwise. Operate weapon controls to include charging handle and magazine release with the stock in all positions to determine compliance with requirement. Fire weapon with stock extended and stowed to verify function.
4.2.1.3 Ammunition magazines. Verify the SCAR H magazine will accept 20 rounds of M80 ammunition and the SCAR SV magazine will accept 10 rounds. With dummy 7.62mm ammunition verify fit and function with the SCAR. Inspect and document the size/weight and general construction characteristics of the magazine. The magazine will undergo all rough handling, and extreme use requirements of the basic weapon, and shall remain intact and reliable.
4.2.1.4 Sling mounts. The SCAR H with sling will be inspected and tested to determine compliance with the requirement of 3.2.1.4.
4.2.1.5 Surface finish. Inspect surface finishes of the SCAR H for compliance with the requirements of 3.2.1.5.
4.2.1.6 Weapon internal storage. Inspect SCAR H to determine if a storage compartment meeting the requirements of 3.2.1.6 is present.
4.2.1.7 Weapon controls.
4.2.1.7.1 Trigger pull. The trigger pull will be tested as follows: the unloaded weapon will be fully cocked with the safety off. A force will be gradually applied to the center of the trigger bow in a direction parallel to the barrel. A spring scale will be used to apply the force to the trigger. The amount of force required to release the sear will be read directly from the spring scale. Data from ten iterations will be recorded to assess consistency. The weapon will also be manually tested to assure that the trigger pull has minimum creep with a predictable break. After partial or complete trigger pull the trigger must return under spring action to its normal forward position.
4.2.1.7.2 Magazine release. Operate the magazine release both left and right handed to verify requirements of 3.2.1.7.2. Check to verify that an empty magazine drops free of the weapon from its own weight.
4.2.1.7.3 Bolt hold-open. Operate the weapon with an empty magazine to verify requirements of 3.2.1.7.3.
4.2.1.7.4 Charging handle. Operate the charging handle with the left and right hand while the stock is in all positions to verify requirements of 3.2.1.7.4.
4.2.1.7.5 Safety/selector switch. Selector lever/safety shall be set in SAFE position and shall be checked to assure the rifle cannot be fired. Selector lever/safety shall be operable by either left or right-handed users. Verify that position of selector lever/safety can be determined by both sight and touch. Move the selector lever/safety and verify that tactile signature is provided with minimal noise and that movement from Safe position to Full-auto position does not exceed 90 degrees. Inspect weapon-firing mechanism to verify that the hammer/striker cannot impact/move the firing prior to actuation by the trigger or before the bolt moves into the locked position. Additional testing shall comply with TOP 3-2-504, paragraphs 5.3, 5.4, 5.5, and 5.6.
4.2.1.7.6 Iron sights. Examine front and rear iron sights to determine compliance with the requirement of paragraph 3.2.1.7.6. Zero weapon at 25 meters and 10 meters to determine if iron sights have sufficient correction to accomplish task. Determine that sights maintain settings once zeroed, and if sights are prone to damage by rough handling. Confirm during accuracy testing that sights have enough correction to zero and hit the 600-meter target
4.2.1.8 Workmanship. Inspect the weapon for compliance with the requirements of 3.2.1.8.
4.2.1.9 Identification markings. Markings will be examined to verify compliance with 3.2.1.9 to confirm that markings are visible and located appropriately.
4.2.2 Design requirements.
4.2.2.1 Modularity. Inspect the SCAR H to verify that it is able to fire NATO standard 5.56x45mm munitions as referenced in paragraph 2.2.1. Verify that the SCAR H is available with three separate barrel lengths for varying mission requirements. Verify that barrel length changes can be accomplished either by upper receiver or barrel change at the unit level with special tools as necessary. Identify special tools. Document the amount of time changing modular components to verify compliance with 3.2.2.1. Effectiveness of modular barrels will be confirmed during accuracy testing per 3.2.3.11.1. Verify the headspace of assembled modular components falls within safe operating limits for the 5.56mm NATO. Verify that the SCAR H has a free-floating barrel.
4.2.2.2 Field stripping. Break down weapon per field stripping instructions in operators manual to verify compliance with 3.2.2.2. Evaluate conformance to requirement to access weapons components, that weapon is incapable of improper assembly, and that any pins are captive. Determine ease of performance during OA under various modes of dress, day/night operation, and duress of severe environments.
4.2.2.3 Parts interchangeability. Three random SCAR samples are to be inspected then broken down into component parts. Parts will then be exchanged between weapons and assembled with the components of other like weapons to verify compliance with 3.2.2.3. Upon reassembly, weapons will undergo safety inspection for headspace, safety, trigger pull, accuracy, and a 200 round function test.
4.2.2.4 Commonality of SCAR systems. Inspect weapons for commonality with SCAR L samples, to review for operational controls and parts commonality compliance with 3.2.2.4.
4.2.2.5 SOPMOD compatibility/interoperability. Verify that the SCAR H has a rigid MIL STD 1913 rail at the 12:00 position running continuously from the rear sight to the front sight, which is mounted to the upper receiver, or is integral to the weapon and has alternate grooves numbered per 3.2.2.5. Verify that the SCAR H is compatible with the Enhanced Grenade Launcher Module (EGLM). Verify that the SCAR H in any barrel length configuration is able to mount (EGLM) 40mm grenade launcher on 6:00 position and withstand 40mm recoil without damage to the system. Verify that the SCAR H also has additional MIL STD 1913 rails at 3:00, 6:00, and 9:00 in the fore-arm/hand guard area. Verify that all rails are capable of maintaining the bore sight alignment. Verify that SOPMOD and Modular Weapon System aiming devices that attach to these rails maintain weapon zero while conducting routine firing combined with combat movement and operational training drills.
4.2.2.6 Muzzle brake and sound suppressor. Verify that the SCAR H is able to accept a sound suppressor. Verify that the SCAR function is not degraded by the installation of the sound suppressor and its muzzle interface. Verify SV uses a suppressor that does not degrade precision fire capability by adding additional dispersion to what the weapon does without suppressor attached.
4.2.2.6.1 SCAR H sound suppressor. Measure and test to verify that the requirements of 3.2.2.6.1 are met. Inspect the suppressor for dimensional compliance, as well as sound suppression measured by the procedures detailed in TOP 1-2-608. Service life, effect on accuracy/point of impact shift, shall be evaluated during the reliability testing stated in paragraph 4.2.3.9. Ease of attachment will be examined during endurance testing. The SCAR H 7.62mm suppressor and the SOPMOD 5.56mm suppressor used on the SCAR L will be inspected to ensure that a dangerous condition of attaching the 5.56mm device to the 7.62mm SCAR H is not possible. The SCAR H suppressor shall be subjected to all environmental testing applied to the SCAR H per MIL-STD-810F.
4.2.2.7 Corrosion control. Verify the SCAR H is protected with a durable corrosion resistant coating, and constructed of corrosion resistant materials after conducting salt fog tests in accordance with MIL-STD-810F, Method 509.4. Verify that the coating minimizes the attraction of dust and contamination per Method 510.4 MIL-STD-810F. Verify that the coating materials are able to protect the SCAR H from degradation after exposure to NBC decontamination processes.
4.2.2.8 Fungus. SCAR H shall be tested to verify requirement of 3.2.2.8 using testing in accordance with MIL-STD-810F, Method 508.4.
4.2.2.9 Static load. Position the weapon in a fixture in the normal firing position (horizontal); place a 246 pound weight on the center of the weapon over a width of 4 inches for one minute. Repeat the test for all four sides of the weapon. Verify that the requirements of paragraph 3.2.2.8 are met, by firing weapon for accuracy and zero.
4.2.3 Performance Characteristics.
4.2.3.1 Caliber, chamber and headspace. Verify that the SCAR H is chambered for 7.62X51mm NATO ammunition. Headspace shall not be less than 1.6355 inches or more than 1.6380 inches when measured to the .303 inch datum diameter on the first shoulder of the chamber. Fire the SCAR H variations with 200 round samples of 7.62x51mm ammunition found in paragraph 2.2.1 to verify weapon function.
4.2.3.2 Non-catastrophic failure. Verify that the SCAR is designed to fail in a non-catastrophic manner when subjected to operational, environmental, and operator induced abuse. Verify that the SCAR does not fail in such a manner as to become a hazard to the operator or friendly force in the immediate vicinity. Failure inducing conditions may include but are not limited to: bore obstruction, overheating, and environmental extremes. Verify that the weapon is able to fire with various bore obstruction without catastrophic failure.
4.2.3.3 High weapon temperature operation. To determine compliance with paragraph 3.2.3.2, verify that after firing 200rds in 5 min, the operator, with unprotected hands, is able to operate the weapon and all controls without injury such as burns from excessive heat.
4.2.3.4 Cartridge ejection. Verify that spent cases are ejected away from other shooters in parallel or on line as well as away from the face and body of left-handed operators. Determine if the SCAR H has a brass catcher as described in paragraph 3.2.3.4.
4.2.3.5 Sustained rate of fire. Weapon shall be fired at a semi-automatic rate of 25rds per minute for 500 rounds, or until steady state barrel temperature is reached. At that point, a round will be chambered to determine if it will cook-off within 3 minutes. If sample weapon successfully meets the 25rpm requirement, then test will be repeated at 50rpm.
4.2.3.6 Barrel life. Verify that the requirements of 3.2.3.6 apply. Barrel life of 15,000 rds minimum will be evaluated during the reliability test using firing schedule at Appendix A. Barrel life will be determined by accuracy firing for dispersion, and key-holing. Barrel will be considered unserviceable when the average dispersion of a 10 shot group at 300 meters is greater than 2 MOA over the baseline ammunition performance or the presence of key-holing is detected. The barrel will also be considered reject if cracks develop that are detrimental to the safety/function/accuracy of the weapon.
4.2.3.7 System service life. The SCAR H will be tested for compliance with paragraph 3.2.3.7. by an endurance firing of 15,000 rds following the firing schedule outlined in Appendix A. Weapon shall complete the 15,000 rd test without requiring overhaul. Weapons meeting this requirement may continue firing until overhaul is required or 90,000 rds have been fired.
4.2.3.8 Noise emissions. Using procedures for shoulder fired weapons found in TOP 1-2-608, determine by live fire the unsuppressed noise level and verify this does not exceed typical noise levels for same caliber of current service weapons. Suppressor shall be installed and using a sound level meter to determine SCAR L suppressed noise level and verify this is less than unsuppressed level of the current system.
4.2.3.9 Cook-off characteristics. To determine compliance with requirements in paragraph 3.2.3.9, test as follows: under ambient temperature of 70 degrees F, fire 100 rds of ammunition in automatic mode making magazine changes as rapidly as possible. Insert magazine with one round and chamber the round. Keeping rifle pointed in a safe direction verify chambered round does not cook off for a period of 3 minutes. Repeat either adding or subtracting the number of rounds to determine actual point of cook-off. If this test is successful, repeat with ambient temperature of 125 ° F. Repeat process to determine performance with sound suppressor. Reference TOP 3-2-045.
4.2.3.10 Reliability. This requirement will be verified during endurance firing for system service life. Firing schedule in Appendix A.
4.2.3.11 Accuracy. Ammunition used in the precision and targeting paragraphs will be M118LR 7.62mm, with established lot test accuracy/dispersion data. Zeroing procedures supplied by the weapon manufacturer shall be followed before accuracy testing is conducted.
4.2.3.11.1 Precision. Weapon will be fired from a test fixture to verify that the SCAR H (S, SV) does not increase dispersion more than 1.0 MOA at 300m to baseline ammunition performance. The CQC variant will meet the same requirement fired at 100 meters. Three warming shots are to be fired to settle the weapon in the mount. Three 10 round groups will be fired with the average not to exceed 1.0 MOA over baseline ammunition performance. Once weapon is zeroed from the fixture, all three 10 round groups shall print within the boundaries of a circle, the radius of which is 1 MOA plus baseline ammunition performance and the center of which is the point of aim on the E sized target.
4.2.3.11.2 Targeting. To determine compliance with requirements in paragraph 3.2.3.11.2, the requirement shall be performed with weapon mounted in a test fixture with the iron sights adjusted and zeroed to achieve point of aim, point of impact on an E type target at 600 meters using M118LR 7.62x51mm ammunition.
4.2.3.11.3 Probability of hit - semi automatic fire. SCAR H in all variants will test this parameter during Operational Test.
4.2.3.11.4 Probability of hit - Automatic fire. SCAR H in all variants will test this parameter during Operational Test.
4.2.3.12 Proof firing. Verify compliance with requirement as stated in paragraph 3.2.3.12.
4.2.3.13 Lubrication. Verify that the SCAR does not create any new lubrication requirements over existing systems; this will be accomplished during system service-life testing.
4.2.3.14 Rough handling. Weapon will undergo tests to verify the compliance with requirements stated in paragraph 3.2.3.14. During drop tests, a primed empty cartridge will be placed in the chamber to determine that the weapon mechanism is sufficient to withstand shock without firing cartridge. Drop tests will be performed in accordance with TOP-3-2-045. Rough-handling and vibration tests will be conducted per the guidance of MIL-STD-810F, Methods 514.5.
4.2.4 Operational environmental requirements.
4.2.4.1 Environmental requirements. Requirements are to be tested in accordance with MIL-STD-810F processes as specified below:
4.2.4.1.1 Altitude requirements. In accordance with Method 500.3 verify that the SCAR H will operate at altitudes ranging from sea level to < 12,000 feet.
4.2.4.1.2 Mud: The SCAR H will be tested for operation in a muddy environment by placing the weapon in a mud bath, then using field expedient methods for removing the mud, firing one magazine of 20 rds in accordance with the criteria of TOP 3-2-045 to paragraph 3.2.4.1.
4.2.4.1.3 Freezing rain/ice: The weapon will be tested for effect of freezing rain/ice in accordance with Method 521.1. The weapon shall function one magazine of 20 rds following ice removal using field expedient methods.
4.2.4.1.4 Sand and Dust. SCAR H will be subjected to requirements of Method 510.4 without detriment to performance. Weapon will be tested with and without suppressor attached.
4.2.4.1.5 High/Low temperature. SCAR H performance will be evaluated per Method 501.4 and 502.4 respectively to verify performance after or during exposure to extreme temperatures.
4.2.4.1.6 Temperature Shock. SCAR H will be exposed to temperature shock per Method 503.3 without degradation in performance.
4.2.4.1.7 Solar radiation. SCAR H shall not functionally degrade after exposure to solar radiation as tested by Method 505.3.
4.2.4.1.8 Humidity. SCAR H shall be tested to Method 507.3 to verify function per paragraph 3.2.4.1.
4.2.4.2 Airborne operations. Verify conditions stated in paragraph 3.2.4.2. Examine SCAR H compatibility with current static-line and free-fall equipment and procedures, to be conducted during OA/OT.
4.2.4.3 Over the beach capability.
4.2.4.3.1 Drain time. Verify that the SCAR H can be fired within two seconds after emerging from water without detrimental effects to the weapon or operator in compliance with requirements in paragraph 3.2.4.3.1.
4.2.4.3.2 Surf zone operations. Verify that the weapon has firing repeatability (out of water/submerged/out of water) without catastrophic weapons failure. Weapon shall be physically inspected and evaluated by USSOCOM Operators during operational scenarios to determine compliance with 3.2.4.3.2.
4.2.4.3.3 Saltwater immersion. Verify that the SCAR H will function without degradation after being submerged to 66 feet for 2 hours in either fresh or salt water in compliance with requirements in paragraph 3.2.4.3.3.
4.2.4.4 Nuclear, biological, chemical (NBC) operations. Verify that SCAR H suffers no functional degradation as a result of exposure to conditions in paragraph 3.2.4.4. Ensure that SCAR H is not degraded by application of NBC decontamination procedures.
4.2.4.5 Operation suitability/effectiveness. USSOCOM Operators will evaluate the SCAR H during Operational Assessments and Tests to verify requirements of paragraph 3.2.4.5 are achieved.
4.2.5 Ancillary equipment.
4.2.5.1 Sling. The SCAR H sling will be inspected and tested to determine compliance with the requirement in paragraph 3.2.5.1.
4.2.5.2 Bipod. Inspect and test the bipod to determine compliance with the requirements in paragraph 3.2.5.2.
4.2.5.3 Handgrip. Inspect and test the handgrip to determine compliance with the requirements in paragraph 3.2.5.3.
4.2.5.4 Blank firing capability. Verify that the SCAR H has the capability to fire blank ammunition with all barrel variations. Weapon shall fire 140rds of blank ammunition with each barrel combination to assess reliability and durability.
4.2.5.5 Cleaning kit. Verify that a cleaning kit is provided with the SCAR H. Examine and evaluate the material in the kit to determine effectiveness in cleaning weapon. Evaluate at the OA to determine adequacy under field conditions.
4.2.5.6 Jump bag compatibility. Verify that the SCAR H is compatible with the current M1950 Weapons Case, in fit, form, and function.
APPENDIX A: FIRING TABLE
Rationale: The following table will be used in evaluation of the SCAR H.
After each cycle, barrel will be allowed to cool to a temperature that will allow test personnel to hold the barrel in their bare hand. This cycle will be fired a minimum of 160 times for a total of 16,000 rounds. Weapons will be cleaned and lubricated at the beginning of the test and after every 10 cycles.
Firing Cycle Schedule:
Magazine 1 20 rounds automatic fired in 3 to 5 round bursts
Magazine 2 20 rounds automatic fired in 1 continuous burst
Magazine 3 20 rounds semi-automatic rate of 30 rounds per minute
Magazine 4 20 rounds automatic fired in 3 to 5 round bursts
Magazine 5 20 rounds semi-automatic rate of 30 rounds per minute
Total 100 rounds
Note: The SCAR H will be fired with suppressor 25% of the time.
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