TM 9-1275, INSPECTION PRIOR TO DISASSEMBLY

Section 2. Paragraphs 6-9

INSPECTION PRIOR TO DISASSEMBLY

6. General

This section includes specific instructions for inspection of materiel in the hands of troops by ordnance personnel, as well as inspection of materiel undergoing repair in ordnance shops. The inspector must be well versed in maintenance procedure for the materiel, and must have a working knowledge of the tools needed for inspection.

7. Purpose

a. Fundamentally, inspection is for the purpose of determining whether the materiel is serviceable and dependable, or the extent of its serviceability. Serviceability, as interpreted in this section, is the ability of the rifle to perform its intended functions completely.

b. In the event the rifle is found unserviceable, the cause and extent of unserviceability is determined. For weapons in the hands of troops such deficiencies as are found will be corrected on the spot, if practicable. If the rifle is being rebuilt by an ordnance shop, it is thoroughly and completely inspected, and put into the best possible condition that time, materials, and tactical circumstances allow, and returned to the using arm ready for use.

8. Reports

a. Forward suggested improvements in design, maintenance, safety, and efficiency of operation prompted by chronic failure or malfunction of the weapon, spare parts, accessories, or equipment to the Chief of Ordnance, Field Service, Maintenance Division, Washington 25, D. C., with all available pertinent information necessary to initiate corrective action. Report this information on WD AGO Form 486 (Unsatisfactory Equipment Report). Such suggestions are encouraged so that other organizations may benefit.

b. Report to the responsible officer any pertinent carelessness or negligence in the observance of preventive maintenance procedures and safety precautions. This report should be accompanied by recommendations for correcting the unsatisfactory conditions.

Note: The inspector's aim is not to find fault with the using arm, but to be helpful.

9. Inspection Procedure

a. GENERAL.

(1) Each rifle to be inspected is held with the muzzle pointed to the floor, cleared at once, and the chamber inspected for a live round. Be certain that there are no obstructions in the bore or chamber. Do not touch the trigger until after the rifle has been cleared.

(2) Before inspection the materiel is to be thoroughly cleaned to remove any grease, dirt, or other foreign matter which might interfere with its proper functioning or the use of the gages and tools used in inspection.

(3) Inspection, maintenance, and repair of the rifle is to be thorough and exacting, for the malfunction of one small part may cause malfunction of the rifle.

(4) The rifle is to be visually inspected for general condition, operation, and functioning before disassembling for detailed inspection. In such inspection, dummy cartridges are used.

b. SERVICEABILITY STANDARDS AND SPECIAL REQUIREMENTS FOR OVERSEA SHIPMENT.

(1) When performing inspection, the future disposition of the rifle must be considered, as certain serviceability standards have been established (fig. 23) based upon whether the weapons are for using organizations, for oversea shipment, or to be placed in storage for reissue.

(2) In addition to the limits of serviceability which have been established, the following additional special requirements must be adhered to for those rifles which are to accompany troops overseas:

-(a) All safety devices are to operate satisfactorily.

-(b) While it is desirable to have a perfect finish on each weapon, no weapon is to be rejected for oversea use unless the exterior parts have a distinct shine.

-(c) All spare parts and accessories are to be in good condition and on hand.

-(d) Stocks are to have no cracks or splits. All screws are to fit tightly and their slots are to be in good condition.

-(e) The front sight must be properly and securely assembled and have no burrs or malfunctions. Rear sight adjustment for both windage and elevation must function smoothly and show no excessive wear.

-(f) The rifle must not have a shiny gas cylinder. Refer to paragraph 22b for correction of shiny gas cylinders.

-(g) The rifle must be equipped with a new type butt plate which includes a trap.

-(h) The rear sight aperture must have a dull black or gray finish on all surfaces.

-(i) The rifle must function properly when operated by hand.

-(j) Check to be certain that all cleaning and preservative equipment authorized by the standard nomenclature list, oiler, thong case, and combination tool are provided with each rifle.

c. INSPECTION.

(1)- Bolt. Place the clip containing eight dummy cartridges in the receiver of the rifle in the normal manner, and allow the bolt to close. Check the operating rod handle to make certain that the bolt is in the fully closed position. Then slowly retract the bolt to note whether the extractor has fully engaged the cartridge and whether the ejector throws the cartridge from the receiver. Retract the bolt fully and repeat the operation until the entire clip of eight cartridges has been fed through the successive cycle of operations. As the last cartridge is ejected, the empty clip should also be thrown firmly upward and away from the receiver. The operating rod handle and bolt should then remain in the retracted position.

(2)- Trigger pull. The trigger, when pulled, should move to the rear without stopping or gritting. Trigger pull must be greater than 5 1/2 pounds but is not to exceed 7 1/2 pounds for the M1 rifle; and is not to be less than 4 1/2 pounds or more than 6 1/2 pounds for the M1C and M1D rifles. Trigger pull is determined by using the trigger pull weights. (See fig. 15.). With the rifle cocked and with the safety in the forward position, rest the weight on the floor or ground and hook the trigger weight wire onto the trigger so that pressure is applied about 1/4 inch from the lower end of the trigger. (See fig. 4.). Make certain the rod contacts the trigger only and does not rub against the trigger guard or stock, and that the rod and the barrel are vertical and parallel; then carefully raise the weight from the floor. In testing the M1 rifle if the 5 1/2-pound weight trips the hammer or the 7 1/2-pound weight fails to trip the hammer, correct the rifle in accordance with instructions contained in paragraph 26c. Test the M1C and M1D rifles in similar manner, using 4 1/2-pound and 6 1/2-pound weights.

(3)- Clip ejector. Inspect function and spring tension of clip ejector with loaded clip in rifle.

(4)- Rear sight. Try the rear sight elevation and windage knobs for operation. (See fig. 5.). To verify the setting of the rear sight, set the 100-yard elevating knob graduation opposite the index line on the receiver. With this setting it should be possible to depress the aperture from one to nine clicks. Check the cover for tightness and tension relative to the aperture.

(5)- Gas cylinder group. Check the parts of the gas cylinder group for dents, burrs, etc. Check the front sight for looseness, bent or burred wings, and check the blade for "shine".

(6)- Clip latch. Check the clip latch for freedom of movement and tension of the spring.

(7)- Barrel and receiver group.

-(a) The barrel is inspected visually to determine the condition of the bore and the deterioration that has taken place. A gage inspection is then made to determine the amount of wear that has taken place at the origin of the rifling with the breech bore gage. (See fig. 6.). The wear in the chamber or in the related parts affecting headspace is checked with a headspace gage specified in serviceability chart. (See fig. 23.)

-(b) Gage inspection offers no problems, as the tolerances are definitely set; however, classification of barrels by visual inspection is a matter of individual skill and judgment and, therefore, offers many problems. Care in interpretation and application of the standards contained herein will aid in arriving at a uniform point of rejection. The point at which a barrel is rejected by visual inspection varies with the disposition to be made of the rifle immediately following inspection, as explained in b above.

Limits of serviceability for using organizations. The serviceability chart (fig. 23) shows the limits for breech bore (fig. 6) and headspace measurements. (See fig. 7.). If the barrel is pitted to the extent that the sharpness of the lands is affected, or if it has a pit or pits in the lands or grooves large enough to permit the passage of gas past the bullet, it is scrapped. A pit, the width of a land or groove and 3/8 inch long or longer, indicates this condition. Examine barrel for mechanical damage and examine the chamber for deep pits that would seriously affect extraction.
Special requirements of oversea shipment. Breech bore (fig. 6) and headspace measurements (fig. 7) are to be within the limits set by the serviceability chart. (See fig. 23.). A barrel that is uniformly pitted but with sharp edges on the lands may be considered serviceable. Only those barrels which show excessive wear, developed pits, or which have pits cutting into the lands are unserviceable for oversea shipment.
Weapons placed in storage for reissue. Limits for breech bore (fig. 6) and headspace measurements are shown in the serviceability chart. (See fig. 23.). A few fine pits are acceptable. However, the general appearance of the bore should approximate that of a new barrel and should appear to have a minimum of 75 percent of its normal life left.

-(c) The headspace of a rifle is measured as the distance between the shoulder of the chamber and the face of the bolt when the bolt is in a locked position. The minimum headspace measurement is 1.940 inches. Headspace is important because it affects accuracy and safety. If the weapon has excessive headspace when the round is fired, the thin portion of the case expands and grips the wall of the chamber, while the base of the case moves rearward to fill the room allowed by excessive headspace and pulls the case in two. This is called a ruptured cartridge case and allows gas to enter the receiver, often severely damaging the weapon. To obtain the headspace measurement, the headspace gage is placed on the face of the bolt and so positioned that the ejector enters the clearance cut on the base of the headspace gage. If the bolt will close fully on a 1.940-inch gage and will not close on the maximum gage as specified by the serviceability chart (fig. 23), the headspace is satisfactory.

Certain gages of early manufacture do not have a bevel around the head of the gage. Do not use these gages on the rifle as interference will be encountered with the fillet around the face of the bolt and erroneous readings will be obtained. Certain other gages do not have the clearance cut for the ejector. When these gages are used, remove the ejector.
The most accurate method of taking headspace is with the operating rod removed, and the reading taken while rotating the bolt lug by hand. If it is found that the headspace of the rifle is over 1.950 inches, check the rifle with a field test bolt. (See fig. 7.). This will determine whether the excessive headspace is caused by a worn bolt or a worn barrel and receiver assembly. If the field test bolt will not close on a 1.950-inch headspace, the bolt is worn and must be replaced; if the field test bolt closes on the 1.950-inch gage, the barrel and receiver assembly is worn and must be replaced.

-(d) With the action open, inspect the receiver for burrs or other deformation.

(8)- Bolt group. Test the bolt for freedom, smoothness of movement, and for locking. Insert bolt in receiver and function with fingers.

(9)- Stock group.

-(a) Inspect the stock for cracks, scratches, bruises, or mutilations. Check for loose or bent sling swivels, burrs, a loose front swivel screw, loose or burred stock ferrule, and for loose or missing butt plate screws. Check the seating of the butt plate, function of the butt plate cap, and the tension of the butt plate plunger spring. Make certain the combination tool, oiler, thong case, and rifle grease container are in the butt-well.

-(b) Inspect the hand guards for cracks and scoring. Check the ferrule and rear hand guard band for looseness and burrs. Check the lower band for looseness, burrs, and loose or missing pin. The pin should be staked. Check the spacer in the front of the hand guard for position and looseness.

[Back to TM 9-1275 "Contents"]

Section

-INTRODUCTION