CARE OF THE GUN

The great importance of the proper care of machine guns desigpated for aircraft work should be fully realized, particularly inasmuch as the guns are working under adverse conditions, and a stoppage due to improper care or adjustment may prove fatal to the operator or at least result in the failure of his mission.

Inasmuch as some little time is always needed to get a machine ready for flight, it will not be necessary to keep the flexible guns mounted on machines, but they should be kept in their boxes until needed for use. It is very important that these boxes be kept covered at all times to prevent the accumulation of dust and dirt on the guns. If it is necessary to keep any guns mounted in readiness for a flight, they should be protected by some sort of covering.

It is absolutely necessary to have the. gun free from all traces of grit when it is ready for.use.

All parts should be thoroughly cleaned and the moving parts covered with a thin film of oil. The oil to be used is a light oil known as airplane machine-gun oil, and is furnished by the Air Service.

It should be remembered that too much oil may give as much trouble as too little due to its tendency to gum and clog the mechanism. The oil should be applied to the moving parts with the fingers or with a cloth patch or camel's hair brush, and used sparingly.

The mechanism should work freely when operated by hand and the proper adjustments should be made. The cause of any excessive friction should be found and remedied. Burrs should be removed from hardened surfaces by means of a stone - never use a file for this.

A short burst should be fired before going up, in order to test the working of the gun.

Never send a gun up in an airplane when there is the slightest doubt of its functioning properly.

AMMUNITION

It is essential that only the ammunition expressly designed for aircraft be used. This ammunition will be packed without clips and bandoleers, but in paper boxes of 20 cartridges per box. The wooden cases in addition to the other standard marking, will bear 'the following words: "For aircraft use - No clips or bandoleers."

In addition, the training insignia carried by airplanes, consisting of star within circle, will be stamped on each end of the packing box,

Each individual round should be carefully inspected. In the absence of cartridge gauges, the best service test applicable to discover defects in shape, is to drop each round into a spare barrel to see that it seats properly. A cartridge with a deep-set or deformed primer should never be tolerated.

Great care should be exercised in loading belts and magazines to see that the cartridges are all in correct alignment. Web belts should be thoroughly dry and should never be used when any round is held loosely enough to allow the least chance of its slipping out of position during flight. The cartridges should never be lubricated, as the oil itself or the dirt which it will collect, will prevent the cartridges from seating properly in the chamber. The loaded belt, whether web or link, should always be placed zigzag in the belt box, never in the form of a roll.

SPARE PARTS

The care of spare parts is a very important matter. Great pains must be taken to keep new parts separate from defective ones.

Spares should be ept in their proper receptacles, wrapped in oiled paper. The lids of the boxes should always be kept closed in order to prevent the accumulation of dust.

A strict account of the spares on hand must be kept and requisitions for additional parts must be made up in time to allow for delay in shipment.

GENERAL PRECAUTIONS TO BE
OBSERVED AFTER A FLIGHT

The gun should be immediately taken apart and every part thoroughly cleaned. Never allow a gun to remain dirty any longer than is absolutely necessary, as the action of the powder residue on the bore may seriously hamper the accuracy. Whenenever possible, all parts should be washed in gasoline, thoroughly dried, and coated with a thin film of oil.

All parts should be given a complete inspection, and any which show the least signs of wear should be removed and replaced with new ones.

It will be necessary to inspect the bore every day for several days and remove whatever residue has "'sweated" out from the metal.

In applying cosmoline to the bore, only a small amount should be used on a cloth patch. The rod should be pulled slowly through the barrel and revolved sufficiently to allow the patch to follow the grooves of the rifling. This will give a thin coating of cosmoline, and any residue which "sweats " out from the metal can be readily detected. If too much cosmoline is applied, chemical action may take place between the residue and the metal underneath the cosmoline and can not be observed. It has been found that a film of cosmoline so thin as to be hardly noticeable is sufficient to prevent rust even when the barrel was exposed to the weather for a considerable length of time provided the bore was clean before the cosmoline was applied.

Rusty, worn, and pitted barrels cause tracer bullets to become "dead," i. e., they will not ignite.

INSPECTION

All guns, spares, belts, and magazines should be inspected by the officer in charge of guns at least once a week. The guns should be completely stripped and the parts laid out for inspection.