Extractor Ruptured Cartridge

ruptured cartridge case extractor j cal. 50 4933 -7 160041

Figure 110. Caliber .50 ruptured cartridge case extractor.

ruptured cartridge case extractor j cal. 50 4933 -7 160041

Figure 110. Caliber .50 ruptured cartridge case extractor.


Set Headspace And Timing Cal
Figure 111. Ruptured cartridge case extractor alined with the chamber.

remove the ruptured case and extractor (fig 110 (2) Always check headspace and timing after and 111). a ruptured cartridge occurs, and set if necessary-


39. General a. Gun Maintenance. The importance of a thorough knowledge of care, cleaning, and maintenance of the machinegun cannot be overemphasized. Care, cleaning, and maintenance determine whether or not the gun will function properly when needed. The bore and chamber must be properly maintained to preserve accuracy. Because of the close ñt of working surfaces and the high speed at which the gun operates, the receiver and moving parts must be kept clean, correctly lubricated, and free from burrs, rust, dirt, or grease to insure proper, efficient functioning.

b. Mount Maintenance. The care, cleaning, lubrication, and adjustment of the mounts used with the gun are no less important. The functioning of the gun and mount together determine overall effectiveness. All accessories and equipment used with the gun and mount, including ammunition, must be properly maintained.

c. Maintenance System. To inBure proper care of the machinegun, It is necessary to have a system of maintenance or a standard operating procedure (SOP) for the frequency of cleaning. Each gun should be cleaned as soon after firing as possible and each time it is exposed to field conditions. Under combat conditions, the gun should be cleaned and oiled daily. Under extreme climatic and combat conditions it may be necessary to clean and lubricate more frequently. Under ideal conditions, where the gun is not used, and is stored in a clean, dry place, it may only be necessary to inspect, clean, and lubricate every 6 days. The gun should be disassembled, cleaned, and oiled in a clean, dry location, where it is least exposed to moisture, dirt, etc. Maintenance and preparation for storage over a longer period of time is covered in ordnance regulations <Ord 8SNL A-l). If possible, keep the gun covered with a gun cover, canvas, tarpaulin, or poncho, when not in use.

d. Cleaning Materials.

(1) Rifle bore cleaner is used to clean the bore of the machinegun barrel after firing. Immediately after using bore cleaner, dry the bore and any parts of the gun exposed to the bore cleaner ; then apply a thin coat of special preservative lubricating oil.

(2) When bore cleaner is not available, water can be used. Hot or cold water can be used ; however, warm, or hot, soapy water is recommended. After using soap and water, dry the barrel and apply a thin coat of special preservative lubricating oil.

e. Lubricating. "

(1) Special preservative lubricating oil (PL-SPECIAL). A thin oil used for lubricating at normal and low temperatures and for providing temporary protection against rust. The entire gun can be lubricated with this oil.

(2) Lubricating oil (LSA). Should be used to lubricate all friction-producing parts of the gun as well as exterior partB exposed to the elements. LSA will not burn off during firing or wash off during rain.

(8) Cold climates (consistently below 0 degrees F). Lubricate the gun with weapon lubricating oil (LAW) and keep it covered as much as possible. For further information, see TM S-207 and FM 31-70.

(4) Hot, humid climates. Inspect the gun more frequently for signs of rust. Keep the gun free of moisture and lightly oiled with lubricating oil (LSA).

40. Core and Cleaning Before, During, and

After Firing a. Before firing (when thfe situation permits), take the following steps to insure efficient functioning of the machinegun:

(1) Disassemble the gun into its major groups or assemblies.

(2) Clean the bore and chamber, but do not oil them.

(8) Clean all metal parts thoroughly and apply a light coat of oil to all metal parts which do not come in contact with the ammunition. (See app C for a checklist of before, during, and after firing care and cleaning.)

f>. To insure complete removal of powder residue and primer fouling from the bore of the machinegun barrel, the bore should be cleaned once each day, for at least three consecutive days after firing. The bore sweats out this fouling or residue, and cleaning must be repeated until there is no further evidence of sweating.

41. Care and Cleaning Under Unusual

Climatic Conditions

Extreme cold, hot, dry, and tropical climates affect the gun and its functioning. Care should be taken under these climatic conditions to insure that the gun is cleaned daily with the prescribed lubricant« and protected from the elements by some sort of cover if possible. Further Information on care and cleaning of the gun under unusual climatic conditions can be found in TM 9-1005-21S-10.

42. Care and Cleaning Under CBR Conditions a. If contamination ia anticipated, apply oil to all outer surfaces of the machinegun (DO NOT OIL AMMUNITION). Keep the gun covered as much as possible.

b. If the gun is contaminated, decontaminate by following the procedures outlined in FM 21-40 and TM S-220, then clean and lubricate.

43. Care and Cleaning of Mounts and Accessories a. General The mounts and accessories, such as the ammunition chest and spare parts, should also be kept clean and lubricated. Fainted surfaces should be spot painted when necessary. Moving surfaces should be inspected and oiled with the prescribed lubricant.

b. Tripod Mount, MS. All external surfaces of

Section JV.

44. Preparation

When inspected, the machinegun should be completely assembled, mounted, and have headspace and timing properly set. Inspecting personnel should look for dirt, cracks, burrs, and rust, and

Section V<

45. General

The decision to destroy the gun to prevent its capture and use by the enemy is a command decision, and will be ordered and carried out only on authority delegated by the major unit commander.

a. Destroy the machinegun and mount only when they are subject to capture or abandonment. Destruction must be as complete as circumstances permit.

Lacking time for complete destruction, destroy the parts essential to operation of the gun, beginning with those parts most difficult for the enemy to duplicate.

c. Destroy the same parts of each gun to prevent the reconstruction of a complete gun from several damaged guns, the mount should be kept clean and lightly oiled. Be particularly careful that the pintle bushing is clean and lightly oiled, and that the pintle lock release cam ia well-lubricated and free from grit. The sleeve lock indexing levers and telescopic legs ahould be clean and lubricated enough for ease in use. The mount should be cleaned and oiled with— the same regularity as the gun. Cleaning of the mount can be accomplished in the same manner as the gun.

c. Antiaircraft Mount, MBS. Lubrication on the M6S mount should be light. A drop of oil on the joints of the firing grips, trigger control linkage, slides of the trigger control mechanism, sideplate trigger, sideplate trigger cam, and pintle pivot bolts should be sufficient. Although the pintle does not revolve in the elevator, it should be lightly oiled to prevent rust. When in use, the traversing bearing should be sparingly lubricated monthly. Use automotive and artillery greaae (GAA), injected by a lubricating gun through the lubricating fittings in the base. The bearing should be thoroughly lubricated at all times, but excessive lubrication should be avoided, since excess grease will work out onto the mount.

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  • Jana
    Where is the ruptered cartride remover located on the m240b?
    9 years ago

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