AR-15 Handbook

By Erik Lawrence and Mike Pannone

The most popular handy to use guide to the particulars of the AR-15 type rifle system. This handbook covers common info, malfunctions, care and maintenance, and training tips for those who use this rifle for fun or protections. Written by two Special Forces instructors with decades of experience with this weapon system. A must have for every range bag!

• Language: English
• Publisher: eBookIt.com
• Release date: Apr 26, 2016
• ISBN: 9781941998588

Book preview

B.C.

CHAPTER 1

RIFLE SPECIFICATIONS

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.

CHAPTER 2

DIRECT-IMPINGEMENT GAS SYSTEM THEORY

The AR-15 family of weapons uses a direct-impingement gas system which does not utilize a gas piston, Figure 2-1. When a round is discharged, the bullet passes the gas port in the barrel where gas is tapped off into the gas tube and redirected back to the bolt carrier key, Figure 2-2. The gas enters the gas carrier key and is channeled into an expansion chamber in the bolt carrier. The gas is trapped between the rear portion of the expansion chamber, and the gas rings towards the rear of the bolt. As the gas expands, it is contained by the bolt gas rings and acts on the bolt carrier, pushing it to the rear, and operating the bolt cam pin in the bolt carrier’s cam surface. As the bolt carrier moves to the rear, the bolt rotates 22.5 degrees clockwise, unlocks, and begins extraction of the expended cartridge case.

VARIANTS

Numerous variants are available throughout the country and world, and nearly all work the same way. The key to keeping this system running reliably, with minimum maintenance, is ensuring that all the critical parts related to extraction and ejection and prone to wear are serviceable. These parts are extractor and spring, ejector and spring, gas rings, and buffer spring. If all these are in good serviceable condition and relatively clean, the AR-15 Carbine is extremely reliable.

NOTE

The buffer in a military configured AR-15/M4 should be marked with an H for heavy. This is a heavier buffer and aids in reliability by slowing down the cyclic rate.

Figure 2-1 Direct-Impingement Gas System prior to firing

Figure 2-2 Direct-Impingement Gas System during firing

CHAPTER 3

BALLISTICS

BALLISTICS

The study of the flight characteristics of projectiles (bullets).

TRAJECTORY

The path of a moving