Читать книгу AR-15 Handbook - Erik Lawrence - Страница 3

The AR-15 Carbine/Rifle is a .223 Remington/5.56x45mm lightweight air-cooled, gas-operated, magazine-fed, shoulder-fired rifle. The AR-15 fires from a closed bolt in semi-automatic mode while the military M4 variants are either semi-automatic, burst, or full-automatic.

Figure 1-1 - AR-15A2 HBAR

CALIBER: .223 Remington or 5.56X45mm NATO

WEIGHT WITHOUT MAGAZINE: 8.5 pounds (2.94 kg)

EMPTY 30-ROUND MAGAZINE: 0.25 pounds (0.11 kg)

LOADED 30-ROUND MAGAZINE: 1 pound (0.45 kg)

OVERALL LENGTH: 39 inches (1 meter)

BARREL LENGTH: 20 inches (51 cm)

BORE CHARACTERISTICS: Hard chrome-lined, 6 Lands, 1:9

METHOD OF OPERATION: Gas-direct system; rotating bolt

MUZZLE VELOCITY: 3,200 feet/second (975 meters/second)

EFFECTIVE RANGE: 600 meters

FRONT SIGHT: Adjustable front

REAR SIGHT: M16A4 target-style sight adjustable for windage and elevation to 600 meters

SIGHT RADIUS: 20 inches (51 cm)

FIRE CONTROL SELECTION: Safe – Semi-automatic

UPPER RECEIVER: Flat top with detachable carrying handle

Figure 1-2 - AR-15A2/A3

CALIBER: .223 Remington or 5.56X45mm NATO

WEIGHT WITHOUT MAGAZINE: 7.0 pounds (3.2 kg)

EMPTY 30-ROUND MAGAZINE: 0.25 pounds (0.11 kg)

LOADED 30-ROUND MAGAZINE: 1 pound (0.45 kg)

LENGTH: 29.8 inches to 33 inches (collapsed/extended)

BARREL LENGTH: 16.1 inches (41 cm)

BORE CHARACTERISTICS: Hard chrome-lined, 6 Lands

METHOD OF OPERATION: Gas-direct system; rotating bolt

MUZZLE VELOCITY: 2800 feet/second (884 meters/second)

EFFECTIVE RANGE: 600 meters

FRONT SIGHT: Adjustable front

REAR SIGHT: Dual apertures (0-200m and 300-600) target-style sight adjustable for windage and elevation to 600 meters

SIGHT RADIUS: 14.5 inches (37 cm)

FIRE CONTROL SELECTION: Safe – Semi-automatic

UPPER RECEIVER:

A2 Model- Non-removable carrying handle

A3 Model- Flat top with detachable carrying handle

The barrel rifling twists vary from the original 1 turn in 12 inches (1/12) on the first AR-15 series guns shooting 55-grain bullets, to the current 1/7 or 1/9 twist on the M16A2/A4 service rifle and M4 Carbine. The faster twist is necessary to stabilize the longer and heavier SS109 62-grain bullet with steel penetrator used in M855 ammunition.