Chapter 4.
STOPPAGES AND IMMEDIATE ACTION
16. Stoppages
(a.) A stoppage is any unintentional interruption in the cycle of operation.
(b.) Most stoppages occur because of dirty, worn, or broken parts, and lack of lubrication. The rifleman must be taught to watch for these defects and take corrective action to eliminate them before they cause a stoppage. Some of the more common stoppages, with their usual causes and remedies are shown in table II (para 19). Note that the stoppages are classified according to the steps of the cycle of operation.
17. Immediate Action
(a.) Immediate action is the prompt action taken by the firer to reduce a stoppage. To apply immediate action, pull the operating rod handle all the way to the rear with the right hand, palm up, then release it. The right hand should be held in this manner so it will not be injured in the event of a hangfire. Next, aim the rifle and try to fire it.
(b.) If a rifleman is taught to apply immediate action quickly and properly when his rifle fails to fire, he will be able to reduce most stoppages (table II).
18. Misfire, Hangfire, and Cookoff
(a.) Hangfires and misfires rarely occur. Normally, the firer will instinctively apply immediate action which in most instances reduces the stoppage even when caused by a hangfire or misfire.
(b.) Misfires are caused by one of three factors - the firer, the weapon malfunctioning (due to excessive dirt, etc.), or faulty ammunition. When there has been an excessive number of misfires caused by faulty ammunition, the lot number should be reported to ammunition supply personnel for inspection and determination of disposition.
19. Malfunction
A malfunction is a failure of the weapon to operate satisfactorily. Some of the common malfunctions are discussed below.
(a.) The clip may jump out on the seventh round. This is usually caused by a bent follower arm or bullet guide and can be corrected by replacing them.
(b.) The rifle may fire in bursts of two or three rounds. This is due to the sear being broken, worn, or remaining in an open position. It can be corrected by replacing the trigger assembly.
(c.) The safety may release when pressure is applied to the trigger. This can be caused by a broken safety or by the trigger stop on the safety being worn. It can be corrected by replacing the safety.
(d.) Operating parts which fail to move fully to the rear (short recoil) are caused by:
- Valve leak in gas cylinder lock screw. (Valve not fully seated.)
- Defective operating rod spring.
- Undersized piston. (Caused by the use of abrasives when cleaning the piston.)
.
- INTRODUCTION
.
.- OPERATIONS AND
FUNCTIONING
