THE MAXIM AUTOMATIC MACHINE-GUN.
Fig. 98.
| Weight | 50 lbs. |
| Calibre | Small arms ammunition |
| Rapidity of fire | 600 to 650 shots per minute |
The gun consists of two parts, viz., the recoiling and non-recoiling.
Fig. 99.
Fig. 100.
The Recoiling Part is the barrel and its extension. The barrel is an ordinary rifle barrel with a breech-sleeve to which is secured the extension. The extension of the barrel consists of two vertical steel plates, between which the lock and the gear connected therewith operate on guides and bearings.
Fig. 101.
The Lock bears a vertically sliding piece, D (called the carrier), on its fore end, and does not differ materially from that of an ordinary pistol. It is secured by a divided screw to the connecting-rod, B, of a crank, E, the shaft of which passes through the plates. There is also a handle to the shaft on the right side of the gun outside, and a curved arm to the crank.
The Trigger, F, immediately in rear of the mainspring, M, is actuated by the rod, S, which is operated by the lever, L, having at its upper end a double button. Pressing this button draws back the rod and releases the hammer, G, and firing-pin, H. In rear of the gun is a catch, which when down prevents the lever being pressed forward.
The Non-recoiling Portion consists of the gun-case and the water-jacket. This portion is mounted on trunnions, and has attached traversing, elevating, and depressing gear, and is provided with handles and sights for aiming and the double button for firing.
On the right side of the gun-case is a solidly attached resistance-piece, C. The curved crank-arm, A, is at a small distance from it when the gun is in a firing position, to avoid escape of gas to the rear and fouling of the chamber.
On the left side of the gun-case is a strong spiral spring the rear end of which is connected, by a chain and fusee, with the crank shaft, and the fore end is connected to the gun-case by means of the spring-case; this spiral spring is to bring back the barrel after the recoil and to work the crank; the working strength of the spring can be adjusted by means of the screw at the fore end. The water-jacket surrounds the barrel and is fitted with three openings, one for receiving the water, one for drawing it off, and the third for letting off the steam; the first two are closed by screw-plugs, the third is always open. Both ends of the water-jacket are fitted with stuffing-boxes and glands; these guide the barrel and prevent the escape of water.
In the feed-box, on top of the gun, are two movable pawls and two stationary ones. The movable pawls are connected by a lever to the barrel and are so adjusted that the barrel on recoiling moves them from left to right; by means of a spring they engage behind the next cartridge in the belt, and thus the cartridges move on automatically towards the chamber; when the barrel returns after the recoil, the pawls place the cartridge, still in the belt, immediately above the chamber.
OPERATION OF THE MECHANISM.
Cocking the Lock.—As the lock is brought away from the breech, by the action of the crank, the connecting-rod throws down the hammer, thereby pulling back the firing-pin and compressing the mainspring, which causes the short arm of the trigger to engage under the lug of the hammer, and thus the lock is cocked and cannot act until the trigger is pulled clear of the lug on the hammer. The safety-sear, V, pressed down by a small spring, engages in the upper part of the firing-pin as it is drawn back by the action of the hammer; the firing-pin cannot move forward until this sear is raised; this is done by the connecting-rod, after it rises above the horizontal, thereby securely closing the breech with the lock.
Operation in Firing.—In starting the gun the breech mechanism is operated by hand to insert the first cartridge in the barrel. The gun is then fired by pressing the firing-button. On the explosion of the cartridge the barrel and the gear connected therewith recoil about the distance of one inch. During the recoil the crank-arm comes in contact with the resistance-piece, K, and throws over the crank, bringing the end of the crank-handle onto the spring-buffer. The curve on the crank-arm is so arranged that the crank gets an accelerated movement by which the lock is thrown back clear of the breech and far enough for the carrier to extract the empty case from the chamber and a cartridge from the belt.
The turning of the crank winds the chain attached to the spiral spring round the fusee, thus extending the spring. As the lock goes backwards the carrier is pressed down by its spring, and when in its lowest position the new cartridge is opposite the barrel and the empty case opposite the ejecting-tube.
The action of the spiral spring now brings back the barrel and its extension to their normal position; it also unwinds the chain from the fusee, thus turning the crank to its normal position, which throws the lock forward; as the lock moves forward it pushes the new cartridge into the barrel and the empty case into the ejecting-tube, Q.
During the last one sixteenth of an inch of the forward travel of the lock the carrier is raised by the carrier-levers, which are actuated by the lugs on the fore end of the connecting-rod, and when it arrives at its highest position it is held by a spring.
CARRYING AMMUNITION.
Belts, each holding 350 rounds, are carried in boxes for which there are receptacles on the different carriages. From four to six belts may be carried with each gun. In preparing the belts the cartridges are pushed in until about ⅛ inch of the brass case of the cartridge comes through the belt, or until the ends of the bullets come in line with the ends of the projecting brass strips.
TO LOAD AND FIRE.
Pass the end of the belt through the feed-box from right to left, seize it as it comes through with the left hand, and turn the crank-handle forward with the right hand as far as the spring-buffer; hold it in that position until the belt has been pulled through as far as it will go, and then let the crank-handle return to the firing position of its own accord. Repeat the operation just described. Now press the double button and firing commences.
To unload, it is only necessary to move the crank-handle forward twice and then press the spring underneath the feed-box, which will cause the pawls to disengage from the belt, and draw out the belt from left to right.
CARE OF GUN.
Before using the gun fill the water-jacket through the hole near its end. It holds about 2½ quarts. A water-bag, holding two gallons, is usually carried on the lower ammunition-box under the axle of the gun-carriage.
Oil thoroughly the packing in the stuffing-boxes and see that the barrel goes close home forward.
When the firing is completed, clean the working parts and oil slightly, and draw off water from the water-jacket.
Two locks are provided with each gun.
CARRIAGES.
A tripod weighing 47 lbs. for mountain service. This is sometimes fitted with an axle and two light wheels, and is provided with a light limber, the long leg of the tripod forming the trail. A cavalry-carriage weighing complete 1115 lbs. An infantry-carriage weighing complete 641 lbs.
INSTRUCTIONS FOR DISMOUNTING.
1. Press the spring-catch and open the cover.
2. Remove the feed-box by lifting it up out of the gun-frame.
3. Remove the lock; to do this, turn the crank-handle, which brings back the lock from the barrel, and disengage it from the guides; now let the crank-handle go slowly backwards and at the same time lift the lock upwards; the lock will rise, and when in this position one eighth of a turn will detach its divided screw from the threads on the connecting-rod, when it can be lifted out.
4. Press the spring-box forward and lift the three lugs out of their respective pins, then disengage the spring from the chain and remove the box with the spring.
5. Drive out the pin, and remove the double-button lever with the spring and cup.
6. Drive out the handle-block pin; start the handle-block by slight blows with a mallet or piece of wood from beneath, lift it out of the gun-frame, and remove the rod.
7. Remove the two small slides by sliding them back out of the gun-frame.
8. Draw the recoiling-frame with barrel out from the gun-frame and water-jacket.
INSTRUCTIONS FOR ASSEMBLING.
1. Replace the barrel and recoiling-frame.
2. Replace the two small slides.
3. Replace the rod and put the handle-block in the gun-frame; see that the rod enters its seat in the handle-block before driving the block home, and put in the pin.
4. Engage the double-button lever with the rod, and replace the lever, spring, and cup, and put in the pin.
5. Engage the spring with the chain not wound around the fusee and replace the spring-box.
6. Replace the lock by screwing it into the connecting-rod until the two shoulders meet, then turn the crank-handle forward, guide lock into its guides, and let the crank-handle go slowly back to its place.
7. Replace the feed-box, with the stud in its seat, in the recoil-frame.
8. Close the cover by pressing the spring-catch.
TO DISMOUNT THE LOCK.
(See [Fig. 101].)
All pins enter from right to left. In driving out a pin see that the side of the lock round the pin is well supported.
See that the carrier is in its highest position; then release the mainspring by lifting the safety-sear and pulling the trigger.
1. Take out the pin (1) which secures the mainspring and the clip which keeps the carrier-levers in their places. Remove the mainspring, clip, and carrier-levers.
2. Take out the pin (2) that secures the sear. Remove the sear.
3. Drift out the pin (3) that secures the hammer. Remove the hammer.
4. Drift out the tapered pin (4) that secures the safety-sear. Remove the safety-sear and the firing-pin.
5. Take out the pin (5) that secures the piece which regulates the downward position of the carrier and keeps the carrier in its place. Remove piece and carrier.
6. Remove the cover (6) at the back of the carrier and take out the upper piece and spring; the lower piece is riveted onto the carrier.
TO MOUNT THE LOCK.
1. Put the upper piece and spring into their place in the face of the carrier and slide on the cover (6).
2. Place the carrier in its grooves, put in the piece which holds the carrier in its place, and drive in the pin (5) which secures the piece.
3. Put in the safety-sear and the firing-pin; drive in the tapered pin (4) that secures the safety-sear.
4. Put in the hammer, taking care that its point enters the slot in the firing-pin. Drive in the pin (3) that secures the hammer. When the pin (3) is in place, upset the point slightly by a few blows of a small hammer.
5. Put in the sear and the pin (2) which secures it.
6. Place the carrier-levers in their places; put in the mainspring, taking care its point enters the slot in the firing-pin; put on the clip and drive in the pin (1) which secures the mainspring and clip.
Note.—There may be a little difficulty in entering the pin (1), but a special tool is supplied, which, being entered from left to right, will hold the clip and mainspring in their places, and then the pin (1) can be driven home from right to left, which, in its passage through the hole, will remove the tool.
METALLIC CARRIAGE FOR MACHINE GUNS.
This carriage, manufactured by the Ordnance Department, is designed for any machine-gun; each kind of gun to be provided with its own mount adapted to the carriage, which is made of steel.
The design includes a spherical shield above and a plane apron below the axle for the protection of the cannoneers. The apron is hinged to the axle and is folded up and keyed to the under side of the trail when not in action. The spherical shield can be removed if desired.
The body is the axle, and it and part of the trail make a chest for ammunition in which 1200 .45-calibre cartridges, packed in paper boxes, can be carried.
Two doors, right and left of trail, on inner side, give access to the cartridge-space in the body, and a door on top of the upper end of trail to the cartridge-space in the trail, the two parts being continuous. Lower down in the trail is a tool-box to which the trail-seat, when raised, gives access. The top of the carriage makes a convenient table for tools, feed-guides, and ammunition when in action.
The shield with aperture and disks are so combined that the gun can be readily pointed without exposure.
CHAPTER X.
Theoretical Gunnery. Definitions. General Principles. Probability of Fire. Burst of Shell. Burst of Shrapnel.