20. General
Maintenance includes all measures taken to keep the rifle in operating condition. This includes normal cleaning, inspection for defective parts, repair, and lubrication.
21. Cleaning, Materials, Lubricants, and Equipment.
(a.) Cleaning Materials.
(1.) Bore cleaner (cleaning compound solvent (CR)) is used primarily for cleaning the bore; however, it may be used on all metal parts for temporary (1-day) protection from rust.
(2.) Hot, soapy water or boiling water is no substitute for bore cleaner and will only be used when bore cleaner is not available.
(3.) Drycleaning solvent is used for cleaning rifles which are coated with grease, oil, or corrosion-preventative compounds.
(4.) Stubborn carbon deposits are removed by soaking in carbon removing compound (PCIII-A) and brushing. This process must be followed by the use of drycleaning solvent.
Caution: Individual protective measures must be taken when using compound PCIII-A.
(b.) Lubricants.
(1.) Lubricating oil, general purpose (PL special) is used for lubricating the rifle at normal temeratures.
(2.) Lubricating oil, weapons (LAW) is used for low temperatures (below 0 degrees).
(3.) OE 10 engine oil may be used as a field expedient under combat conditons when the oils prescribed in (1.) and (2.) above cannot be obtained. However, the weapon should be cleaned and lubricated with the proper lubricants as soon as possible
(4.) Rifle grease should be applied to those working surfaces as shown in figure 33.
(c.) Equipment.
A complete set of maintenance equipment (figure 34) and (figure 35) is stored in the stocks of the M1 and M1C rifles and consists of:
22. Cleaning the Rifle
(a.) The rifle must be cleaned after it has been fired because firing produces primer fouling, powder ashes, carbon, and metal fouling. The ammunition now manufactured has a noncorrosive primer which makes cleaning easier, but no less important. The primer still leaves a deposit that may collect moisture and promote rust if it is not removed. The cleaning described below will remove all deposits except metal fouling which is relatively uncommon and is removed by maintenance personnel.
(1.) Chamber. Remove the patch holder from the cleaning rod and insert two patches about halfway through the slot. Dip the patches in bore cleaner, then wring or squeeze the excess fluid from the patches. Screw the M10 cleaning rod together (less the patch holder) and insert it all the way into the bore. Flare the patches out, then insert the patch holder with the wet patches into the chamber. Push the threaded end into the chamber until it touches the cleaning rod. Hold it there with one hand and screw the cleaning rod and the patch holder together. Pull the patches to the chamber; at the same time turning the rod clockwise. Turn the rod several times, wiping the chamber thoroughly. After the chamber has been thoroughly cleaned use the chamber brush in the following manner:
(2) Bore. To clean the bore saturate the bore brush with cleaning compound solvent (rifle bore cleaner) and -
(3) Gas cylinder lock screw with valve assembly. Remove carbon deposits by using bore cleaner, then wipe the part and oil it lightly (do not use abrasives). Check the valve to see that it is not held open by particles of dirt or sand.
(4) Piston of operating rod. Remove carbon from the piston with bore cleaner. Take care not to damage the piston. Oil it lightly after cleaning (do not use abrasives).
(5) Gas Cylinder. Clean the gas cylinder with bore cleaner and with patches.
(6) Face of the bolt. Clean the face of the bolt with a patch and bore cleaner, paying particular attention to its inside edges. Remove the bore cleaner with dry patches and oil the part lightly.
(7) All other parts. Use a dry cloth to remove all dirt or sand from other parts and exterior surfaces. Apply a light coat of oil to the metal parts and rub raw linseed oil into the wooden parts. Care must be taken to prevent linseed oil from getting on metal parts.
(8) Cleaning frequency. The rifle must be thoroughly cleaned no later than the evening of the day it is fired. For three consecutive days thereafter check for evidence of fouling by running a clean patch through the bore and inspecting it. The bore should be lightly oiled after each inspection.
23. Normal Maintenance
(a.) When in use, the rifle should be inspected daily for evidence of rust and general appearance. A light coat of oil (PL Special) should be maintained on metal parts.
(b.) The daily inspection should also reveal any defects such as burred, worn, or cracked parts. Defects should be reported to the armorer for correction.
(c.) A muzzle plug should never be used on the rifle. It causes moisture to collect in the bore, which causes bore rust that is a safety hazard.
(d.) Obtaining the proper rear sight tension is extremely important; without it the sight will not hold its adjustment in elevation. During normal maintenance and prior to firing, the rear sight must be checked for correct sight tension. The indications of improper sight tension are: elevation knob extremely difficult to turn, and elevation knob turn freely without an audible click.
(1) If the elevation knob is extremely difficult to turn, the soldier must rotate the windage knob nut (with the scew-driver portion of the M10 cleaning rod handle) counterclockwise one click at a time. After each click an attempt should be made to turn the elevation knob. Repeat this process until the elevation knob can be turned without extreme difficulty.
(2) In the event the elevation knob is extremely loose and the rear sight aperture will not raise, the windage knob nut must be turned in a clockwise direction, one click at a time, until the aperture can be raised.
(3) To check for proper tension the procedures listed below should be followed:
(4) If the aperture drops, sight tension must be adjusted. To do this the windage knob nut must be turned in a clockwise direction one click at a time until the aperture can no longer be pushed down. If the proper tension cannot be obtained, the rifle must be turned in to the unit armorer.
24. Special Maintenance
(a.) Before firing the rifle, the bore and the chamber should be cleaned and dried. A light coat of oil should be placed on all other metal parts except those which come in contact with ammunition.
(b.) Before firing, rifle grease should be applied to the parts indicated in figure 33. A small amount of grease is taken up on the stem of the grease container cap and is applied at each place. Rifle grease is not used in extremely cold temperatures or when the rifle is exposed to extremes of sand and dust.
(c.) In cold climates (temperatures below freezing) the rifle must be kept free of moisture and excess oil. Moisture and excess oil on the working parts cause them to operate sluggishly or fail completely. The rifles must be disassembled and wiped with a clean, dry cloth. Drycleaning solvent may be used if necessary to remove oil or grease. Parts that show signs of wear may be wiped with a patch lightly dampened with lubricating oil (LAW). It is best to keep the rifle as close as possible to outside temperatures at all times to prevent the collectin of moisture which occurs when cold metal comes in contact with warm air. When the rifle is brought into a warm room, it should not be cleaned until it has reached room temperature.
(d.) In hot, humid climates or if exposed to salt water or salt-water atmosphere, the rifle must be inspected thoroughly each day for signs of moisture and rust. It should be kept lightly oiled with special preservative lubricating oil. Raw linseed oil should be applied frequently to the wooden parts to prevent swelling.
(e.) In hot, dry climates the rifle must be cleaned daily or more often to remove sand and/or dust from the bore and working parts. In sandy areas, the rifle should be kept dry. The muzzle and receiver should be kept covered during sand and dust storms. Wooden parts must be kept oiled with raw linseed oil to prevent drying. The rifle should be lightly oiled when sandy or dusty conditions decrease.
(f.) Special instructions on caring for the rifle when it is subject to nuclear, biological, or chemical contamination can be found in TM 3-220 and FM-21-40.
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