OUR NEW SERVICE RIFLE

By Maj. G. H. Drewry, Ord. Dept.*

M1 Rifle

For more than thirty years the Ordnance Department endeavored to obtain a satisfactory semi-automatic or self-loading rifle to replace the bolt action Springfield. These efforts were not confined to development within the Department. Invitations were extended periodically to gun designers in this country and abroad to submit weapons for test, and tests were made of those received which showed any promise of meeting the specifications prescribed.

During this period of thirty odd years many rifles were received and tested. Mechanisms embodying every known principle of operation were represented in the many types submitted.

Until 1924 efforts had been mainly directed toward developing a rifle to fire the caliber .30 service cartridge. It may be of interest to state here the principal characteristics of the weapon which designers and inventors had been asked to provide:

First: It must be of the self-loading type, adapted to function with the service cartridge.

Second: The weight must not exceed nine pounds.

Third: It must be well balanced and be adapted to shoulder firing.

Fourth: It must be simple, strong and compact, and adapted to ease of manufacture.

Fifth: It must be so designed that the magazine can be fed from clips or chargers.

Sixth: It must be entirely semi-automatic; i.e., so designed that it is impossible to fire more than one shot with each squeeze of the trigger.

Seventh: The mechanism must be so designed as to preclude the possibility of premature unlocking. Preferably the bolt should be positively locked at the instant of firing.

Eighth: The use of special oil or grease or other material applied to the cartridge should not be necessary to the proper functioning of the weapon.

Every model tested to that date (1924) was rejected for failing to meet these specifications in one or more respects, which is eloquent testimony as to the difficulties encountered by designers.

So much effort having been fruitless in providing a satisfactory weapon, it was decided to investigate a caliber smaller than that of the service round. After many tests of various calibers, it was decided that the caliber .276 cartridge developed sufficient power for a shoulder weapon and that the use of this smaller cartridge would facilitate the design of a reliable and durable self-loading rifle within the prescribed weight limit and would also reduce the load of the individual soldier due to the lighter weight of the cartridge. Of the several rifles in this caliber submitted for test, two were outstanding: the Pedersen, designed and developed by Mr. John D. Pedersen; and the Garand, designed and developed by Mr. John C. Garand. Both Mr. Pedersen and Mr. Garand carried on their development work at the Springfield Armory.

John Cantius Garand, inventor of the US Rifle Cal .30 M1--the GARAND!
John Cantius Garand, inventor of the US Rifle Cal .30 M1--the "GARAND"!
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A number of each of these types were manufactured and submitted to the services for test. Both rifles performed very well. However, to adopt a weapon of this caliber involved further complication of the supply problem by the introduction of another type of ammunition.

In the meantime, Mr. Garand, who has been in the employ of the Ordnance Department at the Springfield Armory for the past eighteen years as a designer of automatic weapons, completed a test model of a semi-automatic rifle designed to function with either the Caliber .30, Model 1906, or the caliber .30, Ml, service cartridge. This rifle appeared so promising in its preliminary tests that decision to adopt the caliber .276 was held in abeyance. The results of continued tests of the caliber .30 weapon were so excellent that the caliber .276 project was abandoned altogether and the caliber .30 weapon as developed by Mr. Garand was adopted as the standard shoulder weapon of our Army. This action was taken in January, 1936.

Before such an important step was taken the rifle was required to meet satisfactorily the most rigid tests, not only at the Springfield Armory and the Aberdeen Proving Ground, but in the hands of troops under all conditions likely to be encountered in the service. These tests, of course, consumed considerable time, but since, as was recently stated by the Chief of Infantry in an article in the Infantry Journal, "the whole structure of the military organization still rests on the Atlas shoulder of the doughboy in the mud," it was most important that the rifle to supersede the foremost military rifle be proven beyond question to be its equal as to reliability and accuracy under all conditions.

Many advantages result from the use of a semi-automatic shoulder weapon, the principal ones being: greater accuracy in rapid fire due to the elimination of the distraction of having to operate the bolt by hand; a greater volume of fire per minute per man; more effective fire against low-flying aircraft; and a decrease in time required to instruct new men in marksmanship.

The new rifle, with which our troops are to be equipped, is officially known as the "U. S. Rifle, Caliber .30, Ml," and popularly as the "Garand Semi-Automatic Rifle." It is of the gas-operated type and employs an en-bloc type of clip holding eight rounds. It varies somewhat from the conventional type of gas-operated weapon in that there is no hole drilled in the barrel for taking off gas to operate the mechanism. Instead, the muzzle of the barrel is provided with a sleeve, and while the bullet is passing through this sleeve and just as the base clears the muzzle, a small amount of gas is diverted through a port at the muzzle into a cylinder where it impinges upon the piston of the operating rod, driving it to the rear. The location of the port at the muzzle rather than at some point nearer the breech permits the use of gas at a lower pressure, thereby decreasing the stresses on the operating parts of the rifle.

M1 Rifle Overview
M1 Rifle Overview
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The operating rod extends underneath the barrel from the muzzle to the bolt. A recess is provided in the rod which engages a lug on the bolt just to the rear of the front end of the bolt. This recess and the lug on the bolt have cam surfaces so arranged that as the operating rod moves to the rear, the bolt is first rotated in the same manner as the bolt in the Springfield rifle, until the locking lugs clear the locking recesses in the receiver. After this rotation movement is completed the bolt is carried to the rear by the operating rod. During this movement the operating-rod springs are compressed, the fired case extracted and ejected, and the firing mechanism cocked. When the bolt has reached its rearward position it is immediately carried for- ward to the firing position by the operating rod acting under the impulse of the operating-rod springs. During this forward movement of the bolt the top cartridge in the clip is carried forward into the chamber. This completes the cycle. When the last cartridge in the clip has been fired the clip is automatically ejected and the bolt remains in the open position. As another clip is inserted in the magazine, the bolt moves forward, feeding the topmost round from the clip into the chamber. The firing pin is arranged in the bolt so that it cannot protrude through the firing pin hole until the bolt is fully forward and rotated into its locked position. A manually operated safety is built into the front of the trigger guard which disengages the hammer from the sear when in the "safe" position.

The rifle functions equally satisfactorily with the Caliber .30, M 1 Ammunition, and the Caliber .30, M1906 Ammunition. Ammunition may be loaded into the clips either at the factory or in the field, using a special loading machine, or in an emergency may be loaded into the clip by hand. There are two staggered rows of four rounds in each clip, and it is immaterial whether the topmost round in the clip is on the right or left. The clip can be inserted into the rifle either side up.

The rifle has seventy-two component parts, which include springs, pins and screws; weighs about nine pounds; is forty-three inches overall in length; has a pistol-grip type stock; and provision is made for attaching a bayonet. The rear sight is mounted on the receiver as close to the eye as possible and is of the aperture type, the diameter of the aperture being seven-hundredths of an inch. The front sight is of the blade type protected by guards similar to those on the U. S. Rifle, Caliber .30, M1917.

The rear sight is operated in elevation by means of a knob on the left side of the receiver. Range graduations are engraved on the periphery of the knob in one hundred yard increments up to 1200 yards. Between each hundred yard graduation mark adjustment can be made in 25 yard steps, one click being equal to 25 yards. Windage adjustments are made by means of a knob on the right side of the receiver directly opposite the range knob.

M1 Rifle Parts Diagram
M1 Rifle Parts Diagram
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The amount of care required to be given this weapon by the individual soldier is no greater than in the case of the Springfield. Disassembly for cleaning is simplicity itself, as is the replacement of any parts which may fail. No tools of any kind are required for such disassembly as is normally required in the field for cleaning and replacement of parts. After approximately every one thousand rounds, the gas cylinder plug should be removed and the carbon scraped from the plug. No tools are required for this operation other than a small screwdriver which is provided as a part of the combination tool issued.

In all of the comparative tests which have been made by the services between the Garand and the Springfield, the Garand has come out on top. These have included accuracy, combat and anti-aircraft firings with expert, partially trained, and untrained men. These tests have shown that the fire power of one semi-automatic rifle for short periods is equal to about five single shot rifles.

Each rifle manufactured is tested at the manufacturing establishment for functioning and for accuracy, the accuracy tests being made at a range of one hundred yards, using a machine rest. The average size of the groups of all rifles so far produced has been one and three-quarter inches extreme spread. This is better than the accuracy of the average service rifle and compares favorably with the National Match Rifle.

Rifles are selected from production from time to time and subjected to extensive endurance tests. There have been remarkably few malfunctions or failures of parts in these tests. From the records kept during these tests it has been determined that the serviceable life of some of the major components, such as the bolt and receiver, is well in excess of one hundred thousand rounds. The life of the barrel for average firing is from 8000 to 10,000 rounds.

The rate of fire which can be attained is, of course, dependent to some extent upon the dexterity of the firer. The number of aimed shots at 200 yards for the average rifleman is approximately fifty per minute. The maximum for highly trained riflemen is approximately eighty per minute at this range, and at very close ranges, around fifty yards, a total of one hundred aimed shots are known to have been fired by an expert. Of course, such high rates of fire are not contemplated except in emergencies and they cannot be maintained over any considerable period of time, due to the overheating. An average rate of fire of around thirty shots per minute can, however, be maintained almost continuously without difficulty.

The question naturally arises among those familiar with the "kick" of the Springfield as to the fatiguing effect of firing the new rifle. Although comparative tests between the Springfield and the Garand only show from ten to fifteen per cent less energy of free recoil, there is a noticeable difference in "kick" felt by the individual, which is due to the difference in time of application of the force of recoil. The result is a marked decrease in fatigue from firing. In some of the Armory tests individuals have fired from the shoulder as many as six hundred rounds continuously at a rate of about thirty shots per minute without becoming unduly fatigued. Such an amount of firing in the same period with the Springfield would be next to impossible.

Production of this new rifle is now in progress at Springfield Armory and the difficulties encountered in adapting it to mass production have been no greater than could be expected with any new automatic weapon. None have been encountered that have not been successfully overcome. Production facilities have been provided to the extent of funds which have been made available for that purpose.

The first production models were completed and delivered to troops in August, 1937. Since that time a small but constant monthly production, limited by the equipment available, has been maintained.

The total number of rifles for which funds have been provided to June 30, 1938, is approximately 7500, and it is expected to complete the delivery of these during the current calendar year. For the fiscal year beginning July 1, 1938, funds have been provided for the manufacture of an additional quantity of rifles, and funds have also been provided to greatly increase the equipment, such as new and more modern machines, tools, jigs, fixtures and gages, required in the production of this weapon. These additional facilities will permit a much greater daily production rate than is now available.

In the meantime, the rifles which have been delivered to troops continue to give excellent service. Every organization so far equipped has submitted enthusiastic reports of their performance under all conditions which have been encountered. Demands for this rifle to replace the Springfield are increasing tremendously as its superiority is realized from actual experience with it. This undoubtedly will result in greatly increased yearly appropriations for the production of larger quantities. Even so, it will take several years to complete the rearming of the Regular Army and the National Guard, and as priority will undoubtedly be given to equipping these organizations, it will probably be many years before any of these rifles will become available for other purposes.


*Released for publication by the Chief of Ordnance, U. S. Army. Statements and opinions are to be understood as individual expressions of their author, and not those of the Ordnance Department.