Blackhills 77 Grain Match Ammunition

1. AMMUNITION, RIFLE, CUSTOM LOADED 5.56 CALIBER. PART #D556N9 from Black Hills Ammunition is an exact match and meets all USAMU requirements. AM20

2. a. BULLET: The bullet (projectile) shall be 0.224 inch diameter, weight of bullet 77grains, Hollow Point Boat Tail Match designs also acceptable is Sierra TMK 2015 projectiles.

2b. POWDER; The manufacturer shall establish the charge weight to meet performance requirements. The average chamber pressure of the sample cartridges conditioned at 70 degrees
Plus or minus 5 degrees F, shall not exceed 58,700 psi. Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three STD deviations of chamber pressure shall exceed 64,700 psi. Port pressure minus three STD deviations shall not be less than 16,300 psi for sample cartridges conditioned to 70 degrees plus or minus 5 degrees F.

2c. PRIMER: Small Rifle Match Grade example CCI 450 or 205MAR. These are only examples manufacturer may choose best primer from any source that yield correct performance. The size of the lot of primers used in the cartridges shall be larger than the cartridge lot. A primer lot shall consist of a specific product, made on consecutive work shifts, with no break in the production of that specific product.

2d. CARTRIDGE LENGTH: Overall length not to exceed 2.252 inches when measured from tip of the bullet to the base of the cartridge.

2e.CARTRIDGE LOTS: Lot size shall be no smaller than 75,000 cartridges. Largest lot sizes are preferred. The cartridges shall be New Manufacture ammunition no used components. The assembled ammunition must be in identifiable lots. Each lot shall consist of units of product of a single type, grade, class, size and composition, manufactured under the same conditions, by the same manufacturer, and at the same time. Only one type and weight of propellant shall be used in a lot of cartridges. Each cartridge lot shall contain no more than one lot of primers, one lot of propellant, one lot of projectiles.

2f. CARTRIDGE LOT ACCEPTANCE: Cartridge samples from existing production lots will be tested by USAMU Prior to acceptance of each production lot. Lot acceptance samples will be 400rds. Cost for lot acceptance samples will be inclusive in contract.

2g. MUZZLE VELOCITY: The average velocity of the cartridge projectile, when conditioned at 70 degrees plus or minus 5 degrees Fahrenheit (F), shall be optimum for the specific projectiles accuracy from a 20" Match grade M16 barrel. This will be the manufacturers' choice. Minimum muzzle velocity of 2750 feet per second + or - 20 fps. Max STD dev ES velocity of 60fps, STD Dev velocity19 fps or less. Measured at ambient temperature. Maximum velocity will be determined by manufacturers' choice of projectiles and propellant, primer and brass combinations in conjunction with chamber pressure control limits.

2h. Initial solicitation bid samples for accuracy testing shall be 400 rounds.

2i. ACCURACY STANDARDS Bolt Rifle: Threshold Must AVG 2.25" inches extreme spread or less at 300 yards for five of each ten shot groups. Objective 1.7" extreme spread or less at 300 yards for five of each ten shot groups. Groups will be fired from an accuracy test bolt rifle, from an accuracy fixture. No one ten shot group shall exceed 3.5 inches.

2j. ACCURACY STANDARDS M16 rifle: Must AVG 3.5 inches extreme spread or less at 300 yards for five of each ten shot groups. Groups will be fired from an accuracy test match grade M16 rifle, from an accuracy fixture. No one ten shot group shall exceed 4.2 inches.

2k. FUNCTIONAL CHARACTERISTICS: Ammunition must cycle reliably from STD 20" M16 USAMU match grade rifles. There shall be no weapon stoppages due to the cartridges. No failures to extract, no failures to lock bolt to rear, no hang fires, no misfires either from primer failure or no vent hole in cartridge. No projectiles shall remain in the bore. No bullets shall be pushed back in cartridges during feeding from magazines. There shall be no gas leakage or primer failures due to perforation of primer during firing pin indent, escape of gas through primer cup or around primer cup, no loose primers or blown primers. There shall be no cartridge case casualties due to longitudinal split at any point on case mouth, body, or head. There shall be no cartridge case casualties due to circumferential rupture at any point on cartridge case mouth, body, or head.