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In this section I hope to present a variety of data on the Improve Gardner Gun from both historical and current sources.   Operating instructions, disassembly and nomenclature for the parts of the guns are also presented from an original Pratt & Whitney manual.

See the gun in action here, review some historical accounts, or view the guns related Patents.

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The following is quoted directly from Col. George Chinn's excellent work on the subject of small arms, "The Machine Gun".  No study of the subject is complete without a review of this work.  This is the text of Volume 1, Chapter 9.  This work is a Bureau of Ordnance, U.S. Navy publication and is in the public domain.

Notwithstanding the wide variety of inventions during this era covering all classes of machine guns, few justified the term "improved" which was invariably mentioned at the beginning of each patent claim.  One of the noteworthy exceptions was the Gardner machine gun, invented by William Gardner of Toledo, Ohio, who during the Civil War served in the Union Army as a volunteer in an Ohio regiment and rose to the rank of captain.  Being unable to finance production of the weapon, he sold American patent rights to the newly formed company of Pratt & Whitney, Hartford, Conn., after an agreement had been reached whereby the inventor would receive a royalty on each gun delivered.  This proved to be a wise move on Gardner's part, for Francis Pratt was no novice in gun design. Being a master mechanic and having spent many years in the employ of Colt's Patent Fire Arms Co., Pratt had attained a reputation for being one of the best gun designers in the field.  

The original gun, invented in 1874, was built by hand.  The prototype was turned over to Pratt & Whitney, who in less than 1 year produced a weapon thought capable of meeting military requirements. 

The Gardner gun consisted of two breech-loading barrels placed parallel to each other an inch and a quarter apart.  The barrels were fastened at the breech ends and housed in a single casing.  They were loaded, fired, and ejected alternately by one complete revolution of the hand crank.

To facilitate loading, a special wooden block was filled with ammunition, rim end protruding.  This insured fast alignment of the base of the round with the slots in the feed guide.  These two T slots, machined in a vertical post, dropped the loaded cartridges in correct position for the feed entrance.

To load and fire, one man inserted the rim end of the ammunition projection from the loading block into the feed guide, then withdrew the box from the rounds.  Another turned the crank and aimed the piece.  As the cartridges were fed from the guide, they were replenished by the loader.  In this manner the weapon could be fired continuously.

At the request of Commodore William N. Jeffers, Chief of the Bureau of Ordnance, a test was held at the United States navy Yard, Washington, D.C., in November1875.  In this trial the system was greatly commended by the officers who supervised the test.  They suggested that Pratt & Whitney be allowed to take the weapon back to the factory in order to perfect the new feed system, invented by E.G. Parkhurst, an engineer of that company.  This simple and efficient feed was an arrangement of the cammed levers that transferred the cartridge from the feed guide to the perforated plate, and positively positioned the round in place, retaining the empty case until ejected.  The method eliminated the unreliable gravity feed for which the weapon was originally designed.

A very unique feature was incorporated in the gun's design.  In order to overcome extraction difficulties, a device known as a "shell starter" was used.  This arrangement consisted of two crescent-shaped pieces pinned to the receiver that engaged the rim of the discharged round before unlocking was fully accomplished and cammed in free in the chamber.  A loose cartridge case was thus left to be removed by the conventional extractors.  This method of initial extraction was also a development by Parkhurst, who added many new an improved parts to this already reliable mechanism.

The official report on the working of the Gardner gun mechanism stated that it possessed every quality desirable in a machine gun, namely: lightness, strength, simplicity and durability; all working parts readily accessible; prospects of a feed that positively aligned the incoming rounds independently for each barrel; and an adaptation for firing each barrel at will.  The mechanism worked perfectly and "commends itself to the critical examination and consideration" of the Government.

The weapon had other unusual features, such as a firing pin that was slowly cocked, thereby preventing any sudden impact; and a safety device that allowed ammunition to be run through the weapon without the possibility of discharging the cartridges.

Although General Benet, Chief of Ordnance, was present at the first test at the Navy Yard, the Army showed no inclination to be interested in the Gardner gun, feeling, no doubt that the Gatling was sufficient for the Army needs.

In 1877 additional tests were held to try the new feed system, which was deemed reliable , and to determine the initial velocity, which was measured as 1,280 feet per second.

The weapon used a center-fire metallic-cased caliber .45 infantry rifle cartridge, manufactured by the Union Metallic Cartridge Co. of Bridgeport, Conn.

The barrels are securely screwed into the rear barrel ring, which is pinned fast to the case. The muzzles pass through a similar part called the front barrel ring. The rear ring extends from the back of the housing far enough to contain all bolts together with operating crank and safety stop. A swinging cover, hinged at the forward end of the case, is locked firmly in position by a quick opening latch.  When the cover is raised, the whole operating mechanism is fully exposed, which permits the hasty clearing of malfunctions. The manually operated hand crank is pinned to the crankshaft which is supported by a journal boxes.  These boxes are locked into the rear of the case and serve to protect the swinging cover from side thrusts.  The body of the crankshaft is circular in construction and has journals, or crank pins, for operating the bolts.  These pins are diametrically opposite each other for alternate firing and are eccentric enough to give the necessary motion to the bolts as the move to the front and back, performing the functions of loading the live round, and extracting and ejecting the empty cartridge case.  

The center portion of the driven side of the bolt is machined to fit the periphery of the driving cam.  This is for the purpose of holding the bolt stationary about one-fifth of a revolution of the crank, sot that the time lapse after the firing pin falls will be ample security against hang-fires.

Section View of Firing Mechanism

Each bolt is so constructed that it resembles the letter U, having a horizontal extension which contains the firing pin, firing-pin spring, and extractor.  The U part of the bolt, which works under and around the crank pin, is curved at the inner point to correspond with the outer circle of the crank.  The purpose of the curved front is to hold the bolt in position at the instant of firing. The firing pin extends from the head of the lock through the firing pin spring and sector sleeve, ending in a flange, for locking it into a sear.

The latter is made in the form of a bell crank, pivoted in the center of the bolt.  It holds the firing pin securely and prevents it from coming in contact with the primer until purposely released from its position by action of the crank journal after the lock is in battery in its extreme forward position.  The cocking device, called the sector, or spring compressor, is hinged in a recess of the bolt and engages by means of gear teeth. This pivoting arm is forced against the safety stop, as the main crank advances. The firing pin is then compressed through the medium of the sector sleeve and held safe from accidental discharge but under tension, until released by  the action of the sear.  

The face of the bolt now receives the recoil from the charge's explosion, but is backed up by the crankshaft, thus presenting at the time of discharge practically a solid member.  Each bolt carries a hook-type extractor which cams itself over the rim of the round as it is seated in the chamber.  When the bolt is retracted, the extractor pulls the empty cases from the receiver.  It also performs a double function of preventing cartridges from falling through the perforated plate, as they are mechanically forced down through a kind of feed valve.

This valve is operated of the feed-plate lever, attached to the hinged cover and actuated by the motion of the locks.  It utilizes about one-eighth the stroke of the crank in its forward motion.  The valve is thus given sufficient time to hold both cartridge and empty case down in position while one is loaded and the other ejected.  the valve, which is also fastened to the hinged cover, has a reciprocating movement across the perforated plate, containing two angular openings the size and shape of the cartridges.  The centers of the openings are equidistant from the center line of the chambers of the barrels.

After a cartridge has dropped one-half its diameter into the valve, it is forced by the action of the latter into position for loading, and held positively against the cartridge support.  As the valve is moved back into its original position, the cartridge is cammed downward into the slot in the plate.  At the same time it cuts off the incoming rounds in the feed system, and prevents their obstructing the progress of the one being chambered.

The upper end of the Gardner's feed guide has a trumpet-shaped mouth to facilitate the entrance of the rimmed cartridge heads.  The lower end has a stop which holds the remaining ammunition in the guide whenever the latter is lifted out of its supporting cover. 

The safety is an oblong block with two positions.  It has an angular face against which the projections of the cocking device in the locks may engage when they are moved forward by the operation of the crank.  The block is held in position by two links, which are moved by an arm pinned fast to a shaft passing through the rear of the receiver.  The stop is fastened to the outer end of the shaft.  This arrangement is constructed in the form of a crank having a stop spindle placed in the handle.

Behind the shoulder a spring is located that forces the spindle out of the arm into either of the two stop holes, upper and lower.  When the spindle is in the upper hole, the arm is in line with the barrels and the safety stop is thrown in contact with the cocking arm, by which the firing pin springs are compressed.  this makes the weapon safe, although in a cocked position.  However, with the spindle in the lower hole the safety stop places the cocking arrangement out of gear, making it possible to turn the operating crank without compressing the firing-pin springs.  As a result the operator may crank live ammunition through the weapon with perfect safety.

When worked in conjunction with the feed valve, which can be made to block the remaining ammunition in the feeder, the loaded rounds can be removed from the chambers.  Yet the feeder will remain fully loaded, ready to be put in action instantly.  Thereafter, the crank working the gun can be turned without loading the chambers.  The double safety feature of the Gardner gun ;has many advantages, both for testing and combat, especially when combined with the unique feature of being able to fire the barrels individually or simultaneously.

The barrels can be changed in short order by driving out a lock pin, and then unscrewing, with the use of a wrench, the flats which are machined on the barrels and made accessible by a large opening on the top of the barrel jacket near the muzzle end. This feature is very necessary in this type of machine gun, because it uses a black powder cartridge.  The arrangement permits a visual check and is an easy way to keep the chambers free from the residue left by this kind of propellant. 

*(Note that the above paragraph is completely wrong.  The opening on the top of the jacket is to pour in water or otherwise provide ventilation.  You can remove barrels by removing the front barrel plate and then using a wrench from the front end.  This however is more an armory or depot level procedure and would NEVER be done by an individual in the field for CLEANING.  Headspace and alignment of the barrels is not done casually.  - Joe Lozen)

All these features were incorporated in the Gardner weapon, test fired to the satisfaction of company officials, and proved successful. Finally, after many delays and much correspondence the Navy again took it under consideration.  Commodore Jeffers ordered a final test to be run on the gun, and specified that it be conducted at the Washington Navy Yard range under the supervision of commander H. L. Howison.  The weapon was brought to the Navy Yard by Francis Pratt and Amos Whitney, who not only explained the mechanism and general characteristics, but took turns at the crank operating it during the day set aside for the test, 17 June 1879.

The Weapon was first examined by the board and found to be in good condition, with all parts working smoothly.  The locks were lightly lubricated with a coating of tallow to keep the black powder in a fluid state.  At a given signal the test got underway, with Pratt cranking, and a company representative, Mr. Saunders, feeding the gun.  A 200-round warm-up burst was fired, and the operating parts were examined and found to be in perfect condition.  Then two ammunition boxes were placed on the left side of the gun so that continuous feeding could be accomplished and a 1,000-round burst was fired without incident.  Another check then showed that the fouling on the parts was soft because of the tallow, and the barrel cover was quite hot, but not enough to stop the test.  Firing was resumed again.  When the ammunition was expended from the boxes, a burst of 431 rounds had been fired.  The barrels were then found to be moderately fouled. The mechanism was visually inspected and pronounced in good shape.  However, the barrels and their cover had become so hot that in clearing the weapon of cartridges at the end of the burst, it was recorded that "the live round taken from the right barrel was too hot to hold in the hand." (It is clear that no one had ever experienced a "cook off" up to this time.)

It was decided at this point that the gun should be given a burst that would prove the reliability of the weapon.  A total of 5,000 rounds were prepared for continuous feeding. It was recorded that the time taken in bringing up the cartridges and putting them in the special feeding block allowed some cooling of the weapon before firing commenced.  With 2 men feeding and a third ordnance man helping Whitney on the crank, firing was resumed, and 3,019 rounds were fired without stopping.  The weapon then had its first malfunction when the extractor in the right hand barrel failed to withdraw the empty case.

There was a delay of 1 minute 15 seconds (according to Navy records) before the brass could be removed and firing resumed.  Then after a burst of 359 shots the same malfunction occurred.  The officer in charge allowed the gun's proprietors to take the lock out and examine the extractor hooks.  They appeared in good condition, but when flexed by hand, the right extractor shank appeared not to be as stiff as the left one.  The extractor recess and the grooves int eh barrel were observed to be moderately fouled, but they were not cleaned as the test continued.  Since each failure occurred with the right extractor, it was evident that the ammunition was not at fault.

On the next attempt 690 rounds were fired and another stoppage occurred.  After two more bursts consumed 870 rounds, the ammunition that had been prepared for the 5,000-round test was entirely expended, and firing was concluded for the morning.  The total time consumed in the actual firing of 6, 631 rounds, not counting the delay for cleaning, was found to be 18 minutes 55 seconds.  The five stoppages from failure to extract from the right-hand barrel were recorded as taking 5 minutes 34 seconds.

At noon Messr. Pratt and Whitney were allowed to remove the locks in an attempt to put the right-hand extractor in working order.  The hook on this piece was found to be dulled and it was filed by hand to provide more bite into the inside rim of the cartridge. The shank was bent inward a bit to increase spring tension.

When firing was resumed after lunch, the jackets covering the barrels were found to be still too hot to pick up the gun by hand.  The afternoon test was to be for the purpose of obtaining the best rate of fire.  The company elected to fire a 2,000-round burst, with an average of 380 rounds a minute.  Pratt was not satisfied with this performance and, turning the crank himself, fired a short burst of 100 rounds in exactly 11 seconds, or a rate of 545 rounds per minute.

The barrels were so hot by this time that permission was asked and granted to pour water through the bores until they cooled down to a safe operating temperature.  The weapon then was moved t the sea wall and the muzzle depressed 29(degrees-JL).  With two ordnance men feeding and two assisting on the crank, 430 rounds were run through in a 1-minute burst.  With 3 men feeding and a like number on the crank, the remaining ammunition of the 5,000 to be used in the afternoon test were fired, but the rate of fire was not recorded.

No failure to extract took place in the afternoon firing, as the quick fix resorted to by company officials to overcome the malfunction most certainly proved to be the correct diagnosis and cure.  The total time for actually firing the 10, 000 rounds, again omitting the 5 minutes 35 seconds delay, was 27 minutes 36 seconds.

Mention should be made that Gardner also designed a one-barrel gun, which was bought in limited quantities by the United States Navy. 

Unfortunately for Gardner, the firm of Pratt & Whitney, and the United States Government, the armed services had no interest at this time in the further development of machine guns.  The services were supplied with the Gatling and even this reliable weapon was seldom, if ever, brought into action against the Indians, whose spasmodic uprisings were the only events that warranted the use of such weapons.

The result was that though the Gardner met successfully every test ordered, nothing was done other than the support given by the Navy, which adopted the weapon and purchased a limited number.  Gardner was the first inventor to take into consideration the terrific weight factor involved in the design of hand-transported weapons capable of a high rate of sustained fire.  His single-barrel gun weighed only 70 pounds and its fire power depended solely on how fast the operator could turn the handle.  This feature was recognized by the Navy as desirable for mounting in the rigging and for easy handling aloft and by landing parties where weight and bulk were critical.  

The Army on 15 January and 17 March 1880, ran duplicate trials at Sandy Hook Proving Grounds before a board consisting of Lieut. Cols. S. Crispen and T. G. Baylor and Maj. Clifton Comly.  After a successful performance the board stated that the weapon was reliable, simply constructed, light in weight, and easily operated.  It recommended that the War Department buy a limited number for actual use in the field service, especially since the cost of the weapon was so much less than that of other machine guns offered to the Government.  Despite these recommendations, nothing was ever done officially by the Army to utilize the weapon.  By its inaction the United States lost the benefits of one of the best machine-gun designs of all time.  For, the British Navy was quick to capitalize on the great contribution Gardner made to weapon development.

Influenced by its successful employment of the reliable Gatling, the British Navy had long respected the engineering ability of American gun designers.  The light, inexpensively produced, highly mobile Gardner, to be used in conjunction with the Gatlings, answered some pressing naval problems.  Gardner accepted a cordial invitation to visit England and exhibit his weapon.  The Admiralty not only adopted the gun after trials proved its worth, but it also purchased manufacturing rights whereby the Government would erect a factory for building the arms, provided the inventor would remain in England to supervise their construction.  Gardner agreed, and after terminating his business connections with Pratt & Whitney, he moved to England where he resided until his death.

That the British Admiralty knew what it was after is evidenced by the fact that the army, noting the navy's successful trials of the weapon, also became interested in machine guns.  The government was requested to order a selection committee to examine all existing systems of machine guns for the purpose of military adoption.  This move was very flattering to the navy's foresight in promoting this gun and proving its extreme serviceability, for the army had heretofore been violently opposed to any form of machine gun.  

The British Government granted the request.  The committee, on 21 March 1881, reported that, after exhaustive trials of different  machine guns on 10 points of comparison, the Gardner had been preferred in 9.  It recommended the adoption of the two-barrel gun for all branches of the service where a light weapon could be used and a limber of similar artillery transportation was not required.

The extremely rigorous workout given the weapons under consideration by the committee can be best illustrated by using its own statistics.  The Gardner 5-barrel gun fired 16,754 rounds before a failure occurred, which was considerably more than was done by any of the other 8 guns on trial. Then, each of the 5 barrels fired singly 1,500 shots.  The total number of malfunctions was 24, or a percentage of .014.  Several of the jams were at the very beginning of the trial before the gun, which was new, had been perfectly adjusted.  In the last 7,500 rounds fired for endurance, there were but 5 stops: 4 failures to extract and 1 cartridge bent in the feeder.  Two of these jams were officially credited to accidental dropping of ammunition in the mud by inexperienced loaders.  Leaving out these two stoppages, the percentage drops to 0.04, or four malfunctions in 10,000 rounds.

As another example of the strenuous demands placed on these guns during he examination, the weapons were left uncleaned and exposed to the weather for a full week before firing was resumed.  The 5-barrel Gardner fired without hesitation at the rate of 812 rounds a minute.

That the Royal Navy adopted this lightweight gun long before its official use by the army is credited to hostile opposition from the Woolwich Headquarters of the Royal Artillery.  This branch was prejudiced against machine guns of this type, since the lightweight construction of the weapon removed from the jurisdiction of this organization.  Artillerymen, though tolerating cannon-type machine guns for flank defense, always regarded them as inferior field pieces.

While speaking on the rapid machine gun development of the British Navy, Capt. Charles Beresford in July 1884, in a lecture given before the Royal United Service Institute, stated, "It must be remembered that the navy had had more actual experience in the working of machine guns in the field than any other branch of Her Majesty's Service, as guns for this purpose were supplied to the navy, but not to the army."

The early encouragement to Gardner from the British Government in giving him limited orders for the navy was soon followed by the purchase of large quantities of the weapon for all branches of the service.  Its value was proved in Sudan at the battles of El Teb and Tamasi, and with the naval brigades in the Upper Nile in 1884 and 1885.  A superior method of mounting was designed by a naval engineer which eliminated the limber system and resulted in a tripod arrangement that was used quite successfully.

Long after the Gardner and other hand-cranked guns had ceased to be considered first-line weapons, due to the method of feed and the employment of black powder cartridges, the British attempted to tbring this type of weapon up to a point where it would again be a gun with great possibilities.  

The most serious effort along this line was a belt-fed design that used smokeless powder cartridges.  It was commonly known in this country as the Robertson, being named for the British engineer who was responsible for the devisement.  As the only improvement deserving mention was the belt-feed arrangement, it should rightfully be called the Gardner-Robertson, there being too many features of the earlier gun present not to be given credit.

This hybrid was tested in the United States in competition with other mechanisms and failed so many times during the trial it was withdrawn by its sponsors. Existing records indicate it was never again entered in trials.