Canadian machine gun fun part 1: he's documented some classic machine guns marooned up north (12/20 issue). Now he enjoys some full-auto classics that can, under certain narrow circumstances, still be fired.
Charles Taylor and Richard Collins are partners in a unique business called Movie Armaments Group (phone: 416-465-7376; e-mail: firstname.lastname@example.org) in Toronto. They provide firearms--real and rubber, military uniforms and gear, gun handlers and firearms training personnel to Toronto's important screen-arts industry. And, they are the largest suppliers of this type in all of Canada.
The Canadian gun club to which Taylor and Collins belong is able to reserve several Sundays during the summer months at a Canadian army range fairly close to Toronto. If I fly up to Toronto on an appropriate weekend, it presents me with an opportunity to shoot some of Movie Armaments Group's machine guns with live ammunition.
Be advised, however, that live firing of the Movie Armaments Group weapons is conducted under their gun-smithing license for purposes of testing and checking for reliable operation only, not for recreation. Heaven forbid that the socialist Canadian government would ever permit anyone to take enjoyment from shooting firearms, especially machine guns. 1 selected eight truly classic machine guns that I thought might especially interest SHOTGUN NEWS readers.
They were the British Lanchester submachine gun, the World-War-I-era Lewis Light Machine Gun, the Vickers-Maxim water-cooled medium machine gun, the famous Bren LMG, an incredibly rare German MP38 Submachine gun, an Italian Beretta MP38/42 submachine gun, a Swedish Karl Gustaf Model 45 submachine gun and a Soviet RPK Squad Automatic.
Lewis Light Machine Gun
No small-arms controversy in America has ever created more acrimonious debate than the failure of the U.S. Army's Board of Ordnance (led by Gen. William Crozier) to adopt the Lewis gun during World War I. Tests were conducted in September 1913 with the Lewis gun in competition with the Model 1909 Benet-Mercie automatic machine rifle and the Vickers water-cooled machine gun.
The Lewis Gun experienced 206 stoppages and 35 broken components, compared to 23 malfunctions and zero broken parts for the Vickers and 59 and 7, respectively, for the Benet-Mercie. The Ordnance Board concluded that the Lewis was not superior to the Benet-Mercie, which was already in service.
But Maj. Gen. Leonard Wood declared, "In my private opinion, the Lewis Machine Gun is the best light-type gun yet developed for troops in the field." By 1917, 40, 000 Lewis guns were in service with the British, French, Italian and Russian armies. The British were aghast at the U.S. Army's rejection of the Lewis.
There was, however, a valid, technical reason for the Lewis gun's failure to perform well in the Ordnance Board's tests at Springfield Armory. The early guns submitted for testing had locking cam angles on the bolt body that caused unlocking while residual pressures in the barrel were still too high. This resulted in very high cyclic rates of fire and excessive component failure.
In addition, this premature unlocking had the same effect as too much headspace and thus increased stoppages at an unacceptable level. When Savage Arms Co. finally produced its version of the Lewis gun in caliber .30-'06, which had both, higher velocity and chamber pressure than the .303 British round, added dwell before bolt unlocking eliminated all of these problems
Meanwhile, the Lewis gun went on to successful service with the British, Belgian, Chinese, Czech, Dutch, Finnish; Israeli, Italian, Japanese, Polish, Portuguese and Russian armed forces during and after World War I. By the end of 1916, it was estimated that the British army had fired more than 7 billion rounds through its Lewis guns. During the battle of the Somme, the estimated rate of Lewis-gun fire was more than 15 million rounds every 24 hours.
The Lewis gun is gas-operated, air-cooled, and fires from the open-bolt position. It uses a circular pan magazine, mostly of 47-round capacity, although 97-round drums were often fielded for aircraft deployment. The cyclic rate is usually given as between 500 to 600 rounds per minute. My own tests indicate the actual cyclic rate to be only about 435 rpm with military-issue .303 British ball ammo.
With a loaded magazine in place and the bolt cocked, pulling the trigger releases the bolt group, which moves forward to strip a round from the pan and then chamber and fire it. Some of the propellant gases move through the gas vent in the barrel into the gas cylinder, where they impinge against the piston head to drive it rearward.
Threaded to the rear of the piston rod is the rack, with a row of teeth on the underside that rotate a pinion and wind up the clockwork-type recoil spring, as the piston assembly travels back. The firing pin, which is attached to the striker post on top of the rack, moves rearward about 1.5 inches inside the straight portion of the bolt body's cam slot to leave the bolt locked until the bullet is clear of the muzzle.
The rear of the striker post hits the curved part of the cam slot to rotate the bolt to the left, releasing the bolt's lugs from the locking recesses in the receiver and aligning the lugs with the guide grooves running along the inside of the receiver.
After the rear of the striker post impacts against the rear end of cam slot, the piston assembly carries the bolt to the rear. This system of breech locking was later employed in the World-War-II German FG42 and then subsequently in the dreadful U.S. M60 GPMG. The cycle is repeated as long as the trigger is held to the rear or until the magazine is empty.
On November 11, 1918 the last shot was fired during World War I. By that time more than 180,000 Lewis guns were in service. The vast majority of them, 145,397 to be exact, had been manufactured by the Birmingham Small Arms Company Ltd. (BSA), Birmingham, England,
While somewhat fragile by today's standards, including its easily damaged pan magazines, the Lewis gun was undoubtedly the best LMG to emerge from the trenches of World War I. It weighed only 26 pounds, remarkable for its time frame, as on the other side of the line was only the clumsy, albeit reliable, German Maxim 08/15 "LMG" that tipped the scales at 49 pounds, when its water jacket was filled.
Lewis himself was responsible for the design of the so-called "air ejection" cooling system (aluminum fins around the barrel; which are hidden and protected by a jacket that creates the illusion to some machine gun novitiates that the gun is water-cooled) and this is my principal criticism of the weapon.
It was supposed to evacuate propellant gases out the front. It is my considerable personal experience that it, in fact, drives the noxious fumes directly into the operator's face. Could this have been another reason for the prevalence of gas masks in the British trenches?
The Grand Old Lady of No Man's Land
On August 24, 1916 10 Vickers water-cooled medium machineguns of the British 100th Machinegun Company were grouped in Savoy Trench to support an assault on High Wood in what became the most famous machinegun barrage fired during World War I. The attack was a brilliant success, due largely to the fact that during a 12-hour period 250 rounds short of one million were fired at a range of 2,000 yards by the 10 guns; at least four gas cans of water in addition to all the canteens and urine tins of the Company were emptied into the water jackets for cooling purposes and two soldiers operated a belt-Loading machine without stopping once during that time frame. One gun crew fired over 120,000 rounds.
The Vickers machine gun was adopted by the British as the "Gun, Machine, .303, Mark I" on November 12,1912. It was a lightened and heavily modified Maxim with the toggle action placed upside down so that the toggle broke upwards into the previously wasted space behind the feed block in the receiver. Before simplifications in the manufacturing process increased the weight to 33 pounds, the original Vickers gun weighed 28 pounds, exactly half the 56 pounds of a British Service Maxim.
More than 75,000 Vickers guns were manufactured during World War I. Starting in 1939, another 12,000 were produced during World War II. The Vickers was phased out of British service in 1962 when the FN MAG 58 GPMG was adopted. Many Vickers gunners were, bitterly disappointed.
Apparently to prove a point, in 1963 at Strensall Barracks in Yorkshire, 5 million rounds were fired from a single Vickers gun, which was kept in constant use for seven days and seven nights. The two-man crew was relieved every 30 minutes and the gun fired 250-round belts at the cyclic rate. Barrels were changed every one to one and a half hours. After this ordeal the gun was inspected and gauged with no measurable differences anywhere.
The Vickers is surely one of the great water-cooled machine guns of all time. I personally own four, two chambered for the original .303 British cartridge, a Turkish variant in caliber 7.92x57mm and a South African version in 7.62x51mm NATO. Let's take a brief look at how the Vickers operates and then discuss a few personal hints that I've picked up over the years.
The Vickers is recoil-operated and gas assisted, it uses cloth belts (except for the caliber 7.62x51 mm NATO South African version) that feed from the right. With the first cartridge gripped between the upper and lower portions of the gib on top of the extractor, pulling the crank handle onto the roller once more, while at the same time pulling the belt again sharply to the left and then releasing the crank handle to go forward, the first round is withdrawn from the belt and the second cartridge will be gripped by the extractor's gib. The gun is then cocked and ready to fire.
The trigger is located between the spade grips at the rear of the gun and is operated using the thumbs. There is an elongated, horseshoe-shaped safety lever over the trigger. The second fingers of each hand are used to rotate this safety lever upward, while the thumbs press forward on the trigger.
This releases the firing pin to fire the cartridge. This is also good from a safety aspect, as keeping both hands on the spade grips, safety lever and trigger avoids the very real possibility of losing the tip of a finger between the roller and cycling crank handle. I've seen it happen.
The barrel, mounted in the water jacket with not very waterproof bearings at the front and rear, slides back and forth during the recoil and counter-recoil cycles about 3/4". Inside the receiver, a sliding frame attached to the barrel travels back and forth with the barrel. The breech mechanism is attached to the sliding frame.
When the gun fires, the two .segments of the locking block's toggle joint are in alignment with the barrel and as a consequence, the thrust of the cartridge against the breechblock is translated through the toggle joint to the sliding frame attached to the barrel and thus the recoil momentum generated by the propellant gases inside the cartridge case drive the barrel, sliding frame and breech mechanism to the rear, all locked together.
After approximately 3/4" of rearward travel, a projection on the toggle joint strikes a roller in the receiver, causing the toggle joint to fold. This unlocks the breechblock and permits it to move away from the barrel's chamber end, extracting the empty case and ejecting it straight down through the bottom of the receiver
The barrel, sliding frame and breech mechanism return forward in counter-recoil by means of the fuzee spring under the fuzee cover on the outside of the receiver on its left side. During the recoil cycle, the belt advances and another cartridge is withdrawn from the belt and carried forward into the chamber in the manner described above. As the breechblock returns to its locked position, the sear is automatically released and the firing cycle will continue as long as the trigger is pressed and the belt contains cartridges.
The Vickers has a cup-shaped recoil booster threaded onto the muzzle. Although not necessary, steel, or brass shims, shaped to fit the booster, were often installed to make cleaning the booster easier.
The booster does exactly what its name implies. It traps a small portion of the propellant gases, resulting in added rearward thrust against the muzzle and assisting the smooth functioning of the operating mechanism under adverse conditions.
It was my fascination with the operating mechanism of belt-fed machine guns in general, and the Vickers in particular, that first attracted me to automatic weapons more than five decades ago. I learned many things about these intriguing guns the hard way, by making mistakes.
While I was fortunate to find a very rare Vickers belt loading machine several years ago, prior to that I had loaded thousands of rounds by hand, a very tedious process. For proper functioning, all the rounds must be seated at the same depth in the belt. Used belts are somewhat easier to load than new, unissued belts.
When you own a water-cooled machine gun, you learn to accept that they all leak to a greater or lesser extent. Just live with it. Asbestos-coated twine was originally used to seal the front and rear of the water jacket. Far better are rubber O-rings, but they must fit securely and be neither too large nor small.
The barrel should be covered with a light grease when it's installed in the water jacket. In the beginning, I used water with some radiator coolant in the water jacket. But, far better is machinist's cutting fluid, which both cools and lubricates.
Adjust the tripod so the gun is as low as possible and, if possible, sandbag the legs for added stability. While there were scales made specifically for this purpose, it's best to adjust the tension on the fuzee spring by trial and error to match the ammunition and achieve reliable functioning.
The Greatest Magazine-fed LMG of All Time
At the end of World War I, the British army very much needed a replacement for the Lewis gun, which had numerous deficiencies. It was too heavy for an LMG, bulky and used an easily damaged pan-feed system that produced entirely too many stoppages. It was also subject to excessive parts breakage.
For reasons known only to post-World-War-I decision-makers, the British simply continued to test a seemingly endless variety of LMGs quite indecisively for a period of several years. In' 1930, comparative trials were held between the U.S. Browning, the French Darne, the Danish Madsen, the Swiss Kiraly-Ende, the British Vickers-Berthier and the Czech ZBvz26.
The ZBvz26 had come to the attention of the Small Arms Committee through the British Military Attache in Prague, who had written a glowing report. An improved model, the ZBvz27, was submitted. The subsequent trials were grueling and lengthy.
The Zbvz27 fired more than 10,000 rounds with few stoppages and negligible wear. After more trials and continued modification of the Czech design, a final test of 50,000 rounds was fired in mid-1934 of the ZGBvz34 ("GB" for Great Britain) against the latest heavy-barrel Vickers-Berthier, which proved once and for all that the Czech ZB was the best entry.
Arrangements were then made to produce the gun at the Royal Small Arms Factory (RSAF) at Enfield Lock. The gun was designated as the Bren, from BRno, Czechoslovakia and ENfield Lock. The first model was called the Bren Machine Gun, Mark I, and production commenced in September 1937.
By the end of the year only 42 guns had been completed. But the Bren was manufactured by conventional milling techniques, and the receiver body alone, milled from a single block of steel, required 270 separate operations! This component alone was checked by 550 gages--each made to an accuracy of .0005". The cost to the British government was approximately [pounds sterling]40 Sterling each. (Today, on the U.S. collectors market, a non-restricted transfer specimen of a Bren- Mk I would sell for over US$50,000.)
The Bren went on to serve the British army and those of the other Commonwealth nations for more than half a century. It stoutly helped hold the line on the sands of North Africa, in the jungles of Burma to Malaysia, against the Mau Mau in Kenya, on the frozen hills of Korea, in the Falkland Islands and even in the Middle East during Desert Storm. For my money, this more-than-merely-admirable record for a military small arm marks the Bren gun as nothing less than the finest magazine-fed light machine gun (LMG) ever put into service--by anyone at any time.
Although enormously complex to manufacture, especially by today's standards, the Bren's method of operation is straightforward and contributes in" no small measure to its tremendous reliability. Magazine-fed and gas-operated, the Bren fires from the open-bolt position. The retracting handle is non-reciprocating and can be folded when not in use (Mk I only).
When the Bren is fired, a small amount of the expanding propellant gases move through the barrel's gas port (after the bullet has moved past this point), through the regulator, striking the piston head and moving it rearward. During this, period of initial pressure buildup, the receiver, barrel, gas cylinder and bipod also recoil rearward approximately .25" on the butt slide.
After this energy has been absorbed by the piston buffer and spring, the spring returns these components, to their original positions. By this means, felt recoil is considerably reduced and component life is greatly enhanced.
An extension attached to the piston supports the bolt body. A post on this extension His inside the hollow interior of the bolt body. When the gun is in battery, two ramps on the extension hold the rear of the bolt up into engagement with the locking recesses at the top of the receiver and against what is called the "locking shoulder."
The piston extension moves rearward through about 1:25 inches of free travel, during which time the bolt remains locked, After this, the ramp support under the bolt is removed and the piston post's inclined surface shoves the bolt's rear end down and out of the locking recess.
This tilting motion provides primary extraction, after which the empty case is withdrawn from the chamber by the extractor claw? A chisel-shaped fixed ejector rides in a groove on top of the bolt and burrs brass over the primer to prevent the latter from falling out. The empty case is pushed through the piston slide's cutout center and expelled downward.
The compressed recoil spring and soft buffer throw the piston forward again. The buffer's low coefficient of restitution helps to hold the cyclic rate to about 500 rpm. Feed horns .on top of the bolt push a fresh round out of the magazine and down into the chamber, as the extractor, claw slips over the rim. After the round is chambered, forward movement of the bolt ceases. The piston continues forward, and the two ramps at the rear of the piston extension lift the bolt up into the locking recess.
The ramps remain under the bolt body to keep: it locked. The piston moves forward another 1.25 Inches, and the front face of the piston post serves as a hammer to drive the spring-retracted firing pin into the primer. This 1.25 Inches of free travel before contact with the firing pin, and the initial non-alignment of the cartridge primer and firing pin, prevent slam fires.
Unlocking before gas pressures have dropped to a safe level is also prevented by the piston's 1.25 inches of rearward free travel and the location of the gas port 15 inches from the bolt's face. It may not sound like it from this description of the firing cycle, but all of this is mechanically simple and extremely safe.
The trigger mechanism provides for full-automatic fire ("A" which is the selector lever's forward position) and semiautomatic fire ("R"'--repetition--the selector lever's most rearward position). The safe position ("S") is located in the middle. The sear is cut out for projection of a tripping lever.
When the selector is set to '"R," the tripping lever's head is raised through the sear's cutout into the piston's path of travel. The piston forces the tripping lever down, and the sear is released upward to hold the piston to the rear. Releasing the trigger repositions the tripping lever against the sear, pushing it down to fire another round.
When the selector is set to "A," the tripping lever is forced down and pulled clear of the piston. Firing will then continue as long as the trigger is depressed and ammunition remains in the magazine. When the selector is set to "S," the trigger is disconnected from the sear by holding the tripping fever in the middle of the sear's cutout.
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|Author:||Kokalis, Peter G.|
|Date:||May 20, 2011|
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