SERVICE RIFLE AND PISTOL AND MARKSMANSHIP

As a Seabee, you make important contributions to the Naval Construction Force (NCF) activities. You are important as an individual as well as a Seabee. The NCF is made up of individuals like you, working together as a team. The ultimate goal of the NCF is success in its construction projects as well as the defense of these projects when needed. Your job is to help achieve that success and to help provide that defense. You may have to fight alone; but most of the time, you will work and help defend a site with other Seabees under a unit or team leader. You can prepare yourself for defense by acquiring the knowledge and skills needed for using both individual and crew-served weapons. You, as a Seabee, are likely to be required to use them; therefore, they are discussed in the next two chapters.

Basic and introductory information about Seabee weapons is given so you can load, fire, field strip, and clean the service rifle, service pistol, light machine gun, light antitank weapon, grenade launcher, and mortar. This chapter covers functioning, mechanical training, assembly and disassembly, loading and firing, ammunition, safety precautions, and marksmanship techniques for both the M16A1 and M16A2 service rifles and the .45 caliber pistol.

THE M16A1 AND M16A2 RIFLES

The M16A1 and the M16A2 service rifles (figs. 3-1 and 3-2) are 5.56-mm, magazine-fed, gas-operated shoulder weapons. Their design provides for either semiautomatic or automatic fire by means of a selector lever.

The M16A1 is equipped with a flash suppressor, but the M16A2 has a flash compensator to hold the muzzle down during rapid and automatic firing.

The barrel of the M16A1 is covered by two aluminum-lined fiber glass handguards (fig. 3-3). These handguards have notches to permit air to circulate around the barrel and to serve further as protection for the gas tube. On the Ml6A2, the handguards are round and ridged (fig. 3-2), making them stronger and easier to grip. The handguards are interchangeable; the handguard retaining ring is also specially contoured and easier to grip.

A "clothespin" biped is issued to, and used by, the automatic rifleman. The biped attaches to the barrel directly beneath the front sling swivel (fig. 3-4). A forward assist assembly (fig. 3-1), located on the right rear of the upper receiver, permits closing of the bolt when the force of the action spring does not.

Figure 3-1.-M16A1 service rifle, 5.56 mm, left and right side views.

Figure 3-2.-M16A2 service rifle, 5.56 mm.

Figure 3-3.-Fiber glass handguard.

The trigger guard adapts easily for use in winter operations. A spring-loaded retaining pin is depressed so the trigger guard swings down along the pistol grip, allowing ready access to the trigger when cold weather mittens are being worn.

Figure 3-4.-Attaching "clothespin" bipod to M16 rifle.

Figure 3-5.-Selector lever pointing to SAFE.

Figure 3-6.-Removing the magazine.

An ejection port cover prevents sand and dirt from getting into the ejection port. It should be closed during periods when firing is NOT anticipated and will open by either forward or rearward movement of the bolt carrier. The M16A2 is an improvement over the M16A1 in the following ways:

. The barrel is 3 to 4 ounces heavier. The new barrel spins the bullet one turn in 7 inches, compared to one turn in 12 inches by the M16A1.

l The Ml6A2 has a maximum effective range of 800 meters, compared to 500 meters for the M16A1. l The front sight post is now square instead of round, making it easier to see.

l The new model no longer fires full y automatic; it fires three rounds only per burst in the automatic setting.

l Left-handed shooters have some protection from injury with a built-in brass deflector located at the rear

Figure 3-7.-Pulling the charging handle rearward.

Figure 3-8.-Locking the bolt open.

of the ejection port. The stock of the rifle is 5/8 inch longer, making it more comfortable and easier to handle. Unless specifically stated otherwise, the following discussion of the M16 rifle applies equally to both the M16A1 and M16A2.

For economy in communication, the following maintenance procedures (clearing, field-stripping, assembling, etc.) for the M16 service rifles are written for the right-handed Seabee. The left-handed Seabee can reverse hand directions for these procedures if it improves their efficiency.