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Gabe Suarez
06-21-2008, 05:42 PM
THE PKM GENERAL PURPOSE MACHINE GUN

Text by Janne Pohjoispaa


Likely inspired by the German MG34 and MG42 general purpose machine guns they encountered during WWII, Soviet designers started to develop their own version of a portable, belt-fed multi purpose machine gun after the Second World War.

While many attempts were made to replace aging Maxims since the 1930's, no satisfactory design had been found. A brainchild of Vasily Degtyarev, the DS-39 was issued to the Red Army just before the WWII, in 1939. It was quickly discovered that the DS-39 had an improperly engineered belt feed mechanism which damaged the cartridge cases while stripping them off from the belt. Tested in the Finnish-Russo Winter War (1939-1940), the DS-39 was found too complicated and liable to malfunctions especially in cold and dusty conditions. The DS-39 was soon withdrew from service.

Next step was the SG-43 (followed later by an improved variation known as the SGM) designed by Petr and Mikhail Goryunov. Goryunov's machine gun was far more reliable than DS-39 and lighter than the old Maxims. Mounted on a wheeled carriage or tripod it served well in the medium MG role, and was converted into a coaxial MG as the SGTM. For infantry the SG43/SGM was just a medium machine gun like the DS-39 or Maxim, however, shortly after WWII, a belt fed version of Degtyarev's DPM light machine gun, the RP-46 was adopted as 'the company machine gun'. The RP-46 was lighter and more manoeuvrable than its belt fed predecessors, but poorly suited in roles other than as a light machine gun.

http://i.guns.ru/club/pk/76a.gif The RPD light machine gun firing an intermediate 7.62 x 39 mm M43 round was considered for the GPMG role. The 7.62 x 39 mm M43 caliber cartridge was already standardised for the AK-47 assault rifles and SKS semi-automatic carbines. One caliber for all infantry small arms would have been an ideal situation, but the 7.62 mm M43 seriously lacked both the penetration and effective range needed in a GPMG. It was dropped and interests were turned for developing a whole new GPMG, firing more potent the 7.62 x 54 R caliber round.

In the early 1950's, two Soviet designers, Grigory Nikitin and Yuri Sokolov started to design a belt fed machine gun chambered for the 7.62 mm rimmed round, while the renowned Mikhail Kalashnikov worked with his own design. The both Nikitin-Sokolov and Kalashnikov weapons were gas operated having rotating bolts and quite similar external appearance. Tests arranged in 1960 revealed that Kalashnikov's design, the PK (Pulemyot Kalashnikova) was more reliable. The PK was also less expensive to manufacture, and it was selected over the Nikitin-Sokolov design. The time for Nikitin and Sokolov would come ten years later. In 1972 the 12.7 x 108 mm NSV heavy machine gun designed by Nikitin, Sokolov and Vladimir Volkov was adopted to replace the DshK and DShKM heavy machine guns - but that is another story.

http://i.guns.ru/club/pk/76b.gif In 1961 Kalashnikov-designed PK-series was adopted as the standard GPMG of the Red Army. Eight years later, in 1969 a product improved version called the PKM (Pulemyot Kalashnikova Modernizirovanniy) was introduced. The PKM can be easily recognised for its lighter, unfluted barrel and a hinged shoulder strap on the buttstock. The PK/PKM series has changed into four configurations:

The PK/PKM is a basic LMG version with bipod.
The PKS/PKMS (PKS - Pulemyot Kalashnikova Stankoviy) is a tripod mounted PK/PKM. Every PK or PKM can convert to a PKS/PKMS while it is placed on the tripod.
The PKT/PKMT (PKT - Pulemyot Kalashnikova Tankoviy) is a solenoid-fired armored vehicle coaxial machine gun, which has no pistol grip or shoulder stock. The PKT is a standard machine gun in recent Russian armored vehicles including the T-72 and T-80 main battle tanks and BMP infantry fighting vehicles.
The PKB/PKMB (PKB - Pulemyot Kalashnikova na Bronetransportere) is a vehicle flex mount MG, and externally quite similar to the SG-43 and SGM. It has no shoulder stock or pistol grip, but is fitted with spade grips and butterfly trigger.http://i.guns.ru/club/pk/77.gif General purpose machine guns chambered for the 7.62 mm rimmed cartridge are quite scarce. However, In addition to those mentioned below, there exists (or have existed) a few other GPMG's chambered for the 7.62 x 54 R cartridge. Czechoslovakia didn't adopted a Soviet machine gun, but fielded the VZ 59 GPMG of their own design. The VZ 59, also produced in the 7.62 mm NATO caliber has not been distributed widely outside the borders of former Czechoslovakia. During WWII, famous Finnish arms designer Aimo J. Lahti designed the L-41 "Sampo" general purpose machine gun chambered for the 7.62 x 54 R round, which was used by Finnish Army in a limited capacity during the Second World War. The L-41 didn't stay in service after the war. In addition to this, there was the 7.62 x 54 R caliber variation of German MG42 developed and built in Finland. The 7.62 x 54 R caliber MG42 never went beyond the prototype stage.

During the Cold War, the PK-series machine guns were widely distributed all over the world and fired in anger in many conflicts. PK-series machine guns have been manufactured or are still in production at least in former Soviet Union/Russia, Bulgaria, Hungary, Rumania, mainland China (Type 80, export only), Yugoslavia (M84) and probably in Poland and former East Germany.

Gabe Suarez
06-21-2008, 05:44 PM
Construction

Like all other true machine guns, the PK fires from an open bolt. Despite that, the basic operating principle follows the familiar Kalashnikov pattern. The PK has a rotating bolt type with two locking lugs, similar to the AK bolt. The PK's bolt larger and more robust; it has larger face to accept a 7.62 mm rimmed round and a single claw extractor similar to the AK assault rifles.

Because the PK fires from an open bolt, the firing pin is temporarily fixed on the bolt carrier. The firing pin can be removed with the bolt, but while the bolt is rotating along its carrier guideway, the firing pin stays locked on the bolt carrier. It will project and strike a primer while the bolt rotates to engage on the locking lugs. The PK's bolt carrier is somewhat similar to the AK slide, except it is turned upside down, it is bigger, heavier and has a less complex shape. The PK is gas operating with a long stroke piston i.e. the gas piston is permanently mounted on the bolt carrier and moves with it. The gas piston and its rod are chrome-plated for better corrosion resistant and pivoted on the bolt carrier. The hinge allows for slight bending of the carrier/gas piston while it is removed/installed. Not all PK series machine guns have a slide buffer, but Hungarian and Yugoslavian made ones do. If you have examined buffers in other machine guns, the buffer may be a fancy name for 1/4 inch thick plate of fiber-reinforced reddish plastic placed at rear end of the recoil spring guide. However, it will reduce recoil by preventing a straight contact between bolt carrier and the receiver, and it also helps with removing and installing the recoil spring guide. The PK family has the gas piston and tube mounted beneath the barrel. The gas tube is fixed on the receiver by a spring steel latch, and it can be separated for cleaning.


The gas block is mounted permanently mounted on the barrel, and connected to the gas tube via the gas regulator. The infantry versions have an exhaust type, three-position regulator. Position "1" is a basic setting, which is used with clean gun, and next steps "2" and "3" are used while action gets more dirty. The gas regulator can be adjusted by using a cartridge or empty case as tool. Theoretical cyclic rate is 650 rpm, according Russian literature. Because the PK action has no proper buffering device, which is required for higher cyclic rates, increasing the cyclic rate with regulator settings is not recommended, because it increases the wear of the receiver and operating parts, and will reduce service life of the gun. The PKT and PKB type machine gun have a different "Venturi" type gas regulator, which doesn't exhaust fumes to the vehicle interior.

The receiver is a U-section stamped from 1.5 mm sheet steel and assembled by rivetings and spot weldings. The receiver has double walls made from two 1.5 mm plates welded one upon another. The receiver top cover is stamped from sheet steel and hinged at front to the receiver and locked at the back with a spring loaded latch. The ejector is similar to the AK's and riveted inside the receiver. The PK ejects empty cases through the ejection port located at left side on receiver. The ejection port has a spring-loaded dust cover. With proper gas selector setting, the ejection cycle is not as violent as the AK cycle and the PK won't damage ejected cases. The PK expels empty cases straight to left at a distance of about 1 m.

The barrel extension is riveted on the front of the receiver in the AKM manner. The barrel extension mounts the gas piston tube and includes the quick-change barrel locking mechanism borrowed from the SG43/SGM machine gun. The barrel extension has a straight boring to accept a cylinderical mounting piece of barrel, and two indexing studs to keep the barrel in right position. A horizontally sliding locking latch fixes barrel to the receiver.

http://i.guns.ru/club/pk/93.gif The barrel is the easiest way to distinguish the PK and its modernized variation, the PKM. The PK has heavier, fluted barrel, while the PKM barrel is lighter (it weighs 2.35 kg and has no longitudinal grooves). The armored vehicle variations PKT/PKTM and PKB/PKBM have even heavier barrels, better suited to the sustained fire role. Like most other small arms of Com-Bloc origin, the PK family barrels have chrome-plated bores and chambers. The PKM bore has four grooves with a right-hand twist of one turn in 225 mm. The barrel length is 602 mm, which doesn't include the flash hider or any other muzzle device. The muzzle has a left-hand metric M18 x 1.5 thread to mount a flash hider or a blank firing adapter. There is an AK-type spring-loaded plunger to hold the muzzle device in correct position. There exists at least two different PK-series flash hiders. Earlier and most common type is similar to the M14 flash hider with five longitudinal slots. More recent model is shorter and conical, also having five slots. Barrel have a pivoted handle, which can be used as the lever to crank the barrel out from its housing.

The trigger housing is mounted permanently underneath the receiver, and it includes the trigger guard. Trigger mechanism, very similar to the RPD is simple, and also very similar to many submachine guns firing from an open bolt. The rotating safety catch located on the left side of trigger housing has two settings: Safe and full-auto. There in no provision for semi-automatic fire, which is, after all, generally considered useless in general purpose machine guns.

The PK/PKM machine guns will usually appear with a skeletonized buttstock made from laminated wood. However, there is no rule without a few exceptions: Some examples of Bulgarian-made PK machine guns have appeared with plastic buttstocks, Chinese Type 80 has skeletonized buttstock, but made from solid wood, and Yugo M84 has also a solid wood buttstock. The PK and PKM have steel buttplates with a trapdoor compartment for cleaning gear. The PKM has a steel shoulder strap. Integral oiler is located in the buttstock. Pistol grip and barrel handle grip plates are usually made from reddish, bakelite type plastic material.
Like most other small arms of Soviet and Warsaw Pact origin, the PK series machine guns will usually feature a black baked enamel finish. Some other examples have a blued or manganese phosphate (parkerized) finish.

Gabe Suarez
06-21-2008, 05:45 PM
Feeding mechanism


The belt fed machine gun firing a rimmed ammunition has a more complicated feeding mechanism than a counterpart chambered for a rimless cartridge. Russians/Soviets have used rimmed 7.62 x 54 R cartridge for more than 100 years, so they have a lot of experience of designing belt-fed mechanisms for rimmed cartridges. Russian designed belt-fed ground machine guns, chambered for the 7.62 mm rimmed round include Degtyarev-designed worthless DS-39, the RP-46 based on a magazine feed DPM light machine gun, Goryunov-designed SG-43 and SGM to name only those entered in service. There was also a series of fast firing, belt fed ShKAS (Shpitalniy - Komaritsky) aircraft machine guns with 1800 rpm rate of fire.

The PK series belt-fed mechanism, which is located over the breech block includes some similarities to the RP-46 and Goryunov designs. The double hooked cartridge gripper is similar to one used in SG 43 and SGM machine guns. Also double receiver covers, the feed cover which includes the feed tray and the top cover, are similar to the Goryunov's. The spring-loaded depressing arm is a take-off from the RP-46.

The PK family utilizes non-disintegrating, closed pocket metallic belt. Actually it is the same as used with the Soviet Maxims, the RP-46 and SG43/SGM machine guns. The PK belts will usually appear in three lengths; for 100, 200 or 250 rounds. The 100 round belt is used with small belt box that can be snapped beneath the receiver. In light machine gun configuration, the 100 rd belt with that assault box is usually employed. The 200 rd and 250 rd belts will fit in bigger belt box, which is the same as is used with the Goryunovs. The 250 rd belt box is a logical choice if fired from the tripod, and it can be readily mounted on the tripod. Both Russian belt boxes are stamped from sheet aluminium. The 250 rd type is all aluminium, while the 100 rd box has an aluminium frame with a steel cover. Both types have canvas carry handles.

The "pull-off" type belts are usually used with machine guns chambered for rimmed rounds, but that is not the only way to go. The most ingenious feeding system for rimmed rounds that I have seen was designed during the WWII by Aarno Lahti of Finland, brother of famous small arms designer Aimo J. Lahti, for the 7.62 x 54 R caliber version of the MG42. The 7.62 x 54R caliber MG42 used a "push-through" type belt, which allowed the use of a standard MG42 fed mechanism. Few prototypes were converted from German-made guns, but license-production never started. The 7.62 x 54 R caliber MG42 left as a technical curiosity.

The PK series belt fed mechanism works as follows: The belt comes to the feed tray from the right side of the PK. The feed tray is located over the chamber, and cartridges are pulled out from the belt to rearwards. While the bolt carrier starts withdraw after a shot is fired, the cartridge gripper pulls the next cartridge from the belt, and bolt carrier movement activates the feed pawl to move leftwards to pull the belt inwards. After travelling about 9 cm backwards the cartridge stops at the feed cam mounted on the top cover, and is dropped over the feed lips of the feed tray by a spring-loaded depressing arm. Just before that the ejector expels an empty case through a spring loaded ejection port on left side of receiver. Bolt carrier continues its withdraw for about 4 cm. When the forward motion begins, the bolt pushes the fresh round towards the chamber, and bolt carrier movement forces the feed pawl to move back to the right. A holding pawl located on the top cover retains the belt. Sights


The PK series machine guns (except a coaxial version PKT, which has no sights) have fully adjustable iron sights. The front sight is similar to the AK assault rifles. Post-type front has curved protective ears, and like the AK's front sight, the PKM front sight is adjustable for both windage and elevation. The tangent-type rear sight has an open, U-shaped notch, and it is similar to ones used with the RPD SAW and RPK LMG, and it is adjustable for both windage and elevation. The PKM rear sight is graduated from 100 m to 1500 m with 100 m increments and 300 m battle sight setting. The sight picture is identical to the AK assault rifles and RPK light machine guns.

Our test specimen has no provision for mounting an optical sighting device, but recent PKM GPMGs will accept the four power 1P29 daytime sight (a copy of British SUIT) or the second-generation 1PN51 passive night sight. The scope mounting rail is located on the left side of receiver. Bipod and tripod


The PK and its modernized version are issued with a folding bipod, which is mounted on the gas tube. The bipod non-adjustable legs are stamped from sheet steel, and it is somehow similar to the RPK bipod. The bipod stays automatically in it's firing position by use of a spring-loaded hinge. While folded, the legs are kept together by a stamped hook. The three-piece cleaning rod is stored on the bipod right leg.

The PK machine gun was originally introduced in 1961 with a tripod designed by Evgeniy Samozhenkov. Samozhenkov's tripod weighed 7.7 kg, almost half less than the SGM tripod, and it still converted easily to both ground fire and anti-aircraft configurations. When the improved the PKM pattern was introduced in 1969, it was issued with a new and remarkably lighter tripod designed by Leonid Stepanov. The Stepanov mount can easily be described as a "light" tripod. Made almost entirely from steel stampings, it weighs only 4.5 kg. It has no buffering mechanism of any sort, and the cradle, which mounts the gun, is connected directly on traverse and elevation mechanism. The Stepanov light tripod can be easily modified ground fire role to AA-configuration.

Each tripod leg can be folded for transport or adjusted for proper height or finding an equilibrium in rugged terrain. While folded for transport, the tripod can be easily carried in field by one man. Like any other tripod, the Stepanov light tripod requires sandbags for maximum stability.

The Stepanov tripod issued with our test gun was manufactured in Kovrov (marked with an arrow inside oval ring) in 1977. It appeared to be unused. Tripod was clean and dry; apparently stored 20 years ago by wrapping it in paper treaded with corrosion inhibiting agent and putting it in a sealed container. During these years all lubricant have dried and frozen most moving parts. It required some muscles and lot of gun oil to get all hinged parts operate properly. Please note: If you are handling wrappings etc. Treated with Soviet/Warsaw Pact corrosion inhibiting agent, bear in mind that it is very poisonous.

In addition to the mounts described above, there exists a flexible vehicle mount, which accepts a standard PK or PKM. A third generation of the PK machine gun


In 1993 a new member of the PK family chambered for the unique 6 x 49 mm round was introduced. Called the Unified Machine Gun (UMG), it is basically similar to the PK/PKM, but has a shorter receiver, apparently with a simplified feed mechanism. The UMG has a longer barrel, while overall length (1150 mm) is approximately equal to the standard issue PK/PKM. This new Russian machine gun is relatively light in weight, as it weighs only 6.5 kg with a bipod. The revealed prototypes have no iron sights, but were fitted with an optical sighting device. In addition to the improved PK machine gun, the SVD based sniping rifle and AK assault rifle chambered for the 6 x 49 mm cartridge are also being developed.

Presumably inspired by the U.S. Army SAW research, the Soviets started developing the 6 mm ammunition primarily intended for infantry machine guns and sniping rifles in about 1980. The first type revealed was the 6 x 53 mm, which launched an 5.2 g bullet with a muzzle velocity of 1150 mps.

About ten years later the 6 x 49 mm cartridge was introduced. It has a rimless case with approximately the same rim diameter (11.4 mm) as a classic 7.62 x 39 mm round. The 6 x 49 mm round has muzzle velocity equal to the 6 x 53 mm, it is also extremely hot having higher chamber pressures than the 6 x 53 mm. While there is a risk for case separation, the case has a circular groove formed near the extractor groove to allow case stretching without risk of separation. For reliable operation, adequate headspace is critical in self-loading firearms. On the other hand, high pressure ammunition will require tight headspacing to be safe. Controlled case stretching as used with certain aircraft cannons allows use of workable headspacing, yet the gun is also safe to fire.
While not so prolific as Mikhail Kalashnikov's assault rifles, his belt fed general purpose machine gun is really an outstanding design. Not the least because it fires a complex rimmed round, but also because it is reliable, easily controllable and easy to operate. It will serve to the foreseeable future in existing forms or firing a new rimless cartridge, which might be a less complicated choice for belt fed weapons.

jlbraun
06-22-2008, 01:21 PM
You can buy a semi-auto PKM:

http://www.vltor.com/projects.htm

The PKM is the first gun I would buy if 922(o) went away tomorrow. (Come on, Heller!)

Frank Pinelander
06-22-2008, 02:31 PM
Generally, I like the PKM. The things I don't like are: difficult from anything other than prone and a "tactical" reload - because of the right hand feed - is complicated.

Solid, robust, reliable otherwise.

The hopper fed belt loaders are sweet.

gunplumber
06-23-2008, 04:17 PM
The hopper fed belt loaders are sweet.

I have a couple of full auto PKMs, and agree that they are a challenge for a right hander to shoot without getting hot brass hitting the left forearm.

But the belt-loader - now that is a fascinating piece of equipment. Sitting in front of the TV, I can load belts faster than my daughter can rip open ammo boxes and dump them in the hopper. Its a really marvelous piece of simplicity in engineering.

karl johnson
06-23-2008, 06:57 PM
The PKM was the first MG I had any real experience with and it worked marvelously. The non-disintegrating link makes its use in an assault more difficult, but I never had to use it for that so I was very impressed by its robust and simple design. I used one as my primary, essentially, for three months. It was less sensitive to dust and fouling in general than the western MG's we had without a doubt.

http://i137.photobucket.com/albums/q227/vonzeitgeist/PKM.jpg

AmericanWarrior
06-23-2008, 08:00 PM
I love machine gunnery!

I always wanted to work with the Iraqi Police/Army PKM's but never got a chance:( ...

But in the end...nothing beats the M240B as far as GPMG's go, nothing!

I thought it was a great idea when Gabe wanted to do a MG class!

Frank Pinelander
06-23-2008, 08:07 PM
But in the end...nothing beats the M240B as far as GPMG's go, nothing!


That statement is a can of worms. The 60, while it has certain shortcomings, is a very versatile weapon with the modern configurations.

Then there's the modern renditions of the MG 42 - sweet, especially in the GPMG role.

karl johnson
06-23-2008, 08:28 PM
I love machine gunnery!

I always wanted to work with the Iraqi Police/Army PKM's but never got a chance:( ...

But in the end...nothing beats the M240B as far as GPMG's go, nothing!

So how would you know if you never got to work with a PKM?

Prairie Fire
06-23-2008, 08:29 PM
As to shortcomings of the M60, bringing the need for safety wire to the party was not one of them.

Dale Hunter
06-23-2008, 08:49 PM
I have had the privlige of working with the PKM, 240B, and the U.S. Ordnance rendition of the M60E4. While all three are outstanding mg's (US ORD. made the M60 what is always should have been) i would take the PKM anywhere, anytime. The PKM is lighter than the 240B, and still slightly lighter (though not much) than the M60E4. Ammunition by far is cheaper in the PKM (like all com bloc ammo vs. NATO).

As far as brute, uncompromising reliability, the PKM (like any kalashnikov system) wins everytime. Also, i found that no matter what type of ammo, if you could squeeze it into the belt, the gun would fire & eject it. IIRC, the PKM i handled, after thousands of rounds, did not experience a single malfunction! the M60E4 choked after we ran 300 rounds of Wolf 308 (steel case seized in the action), the the 240B malfunctioned due to belt issues and ammo issues.

csjavi
06-24-2008, 02:55 AM
The non-disintegrating link makes its use in an assault more difficult
True, but otherwise it feels so good and points so well in an assault, IF the bipod is folded backwards.

gunplumber
06-24-2008, 11:10 AM
I think if I had to carry it, I'd pick the PKM over the M240. Vehicle mounted, perhaps the M240 would win.

I carried an M60 over hill and over dale for many years, and despite the fact that it could be better, I never had any real problems with it (if I put the gas cylinder in right - and tied the trigger group spring with trip wire). The thing is, firing the M60, if it went click instead of bang I usually knew immediately why. On the M16, it could be any of a number of reasons, so I was more confident with the 60. It was inconvenient, but not overly so to parachute with one - except the time my lowering line got stuck and I had to ride it in . . . THAT Hurt.

My daughter likes the PKM, but doesn't like the "short bursts" mantra she keeps hearing from me. She likes the "hold down the trigger till it stops" method of shooting.

http://www.arizonaresponsesystems.com/wp/pkmkjg01.jpg

My buddy lost his leg to a PKM but has considerable combat experience with one - I was surprised at well he could hit targets shooting from the hip. I had less success, even sling supported ( BREN style ). The number one issue with walking fire for a right handed shooter is the hot brass landing in the crook of my left arm. I'm pondering a solution.


http://www.arizonaresponsesystems.com/wp/pkmaquil01.jpg


http://www.arizonaresponsesystems.com/wp/pkmpaul01.jpg


One thing I don't like is the tripod. It is too high for prone, and too low for sitting or kneeling, and the antiaircraft pieces make it overly complicated. I'm working on an adaptor for my 1919's M3 tripod that will be like the one Ohio Ordnance makes (just a lot less than their $750 price tag).


http://www.arizonaresponsesystems.com/wp/pkm12.jpg

What I really do like is that I can afford to shoot my full auto PKMs, RPDs and AKs - something I can't afford to do on my .308 or .223 machineguns.

Dan-O
06-24-2008, 11:21 AM
I love machine gunnery!

I always wanted to work with the Iraqi Police/Army PKM's but never got a chance:( ...

But in the end...nothing beats the M240B as far as GPMG's go, nothing!

I thought it was a great idea when Gabe wanted to do a MG class!

The 240B is doubtless a great MG but I would say the PKM is easily its equal.


Also, FYI,
We are going to be doing some MG classes soon.
Probably in Oct. :D

AmericanWarrior
06-24-2008, 06:36 PM
So how would you know if you never got to work with a PKM?

Because I know a thing or two about machine gunnery, I've done plenty of research into the science of MG emplyment. While yes I dont have any field training/use, after handling and disassembling the wpn I just wasnt that impressed. I still wanted(want) to work with it a little, and wouldnt be opposed to using it in a Iraq-deployment PSD role or whatever...based on reputation...But for a more traditional machinegun mission and when you need the "scientific" edge and precision, I would chose nothing other then a 240B and a properly trained gun crew (and its not the only true MG I've worked with;))

great pics gunplumber

DoctorCheney223
06-25-2008, 09:35 AM
I currently own all three weapons systems (M-60, M240 and PKM) and my personal favorite is the M240.

The PKM is almost to light for it's own good. I do agree 100% with Mark about having to carry it though. It almost feels as light as a Yugo RPK when picking it up and carrying it. My problem with the weapon is that when you start sending rounds down range it starts jumping all over the place. I recently had more time to use all three systems and my opinion changed on the PKM. I also hate using anything other than 100-round belts :mad:

The M240 is just SO smooth. It feels slower than the PKM but faster than the M60 and it does'nt "jump" when shooting. The weight keeps the system on the ground and on target. I like that I can use German MG42/Austrian M74 belts as well as M13 links.

Lastly, I still like the M-60. As Mark stated above, I too haven't had any real issues with mine. I have ran thousands and thousands of rounds through mine and the only issue I have had is a broken bolt cam (parts do break on EVERY weapon at some time). It chugs a long slow enough that you almost feel like you are hand-setting each round into the target. The thing I don't like about the M-60 is that it feels like am using an anemic jackhammer.

http://img86.imageshack.us/img86/1189/postwiki1ej8.jpg



http://img218.imageshack.us/img218/1007/postwiki2sd7.jpg

thanks,
Ron

AmericanWarrior
06-25-2008, 07:09 PM
currently own all three weapons systems (M-60, M240 and PKM) and my personal favorite is the M240.

The PKM is almost to light for it's own good. I do agree 100% with Mark about having to carry it though. It almost feels as light as a Yugo RPK when picking it up and carrying it. My problem with the weapon is that when you start sending rounds down range it starts jumping all over the place. I recently had more time to use all three systems and my opinion changed on the PKM. I also hate using anything other than 100-round belts :mad:

The M240 is just SO smooth. It feels slower than the PKM but faster than the M60 and it does'nt "jump" when shooting. The weight keeps the system on the ground and on target. I like that I can use German MG42/Austrian M74 belts as well as M13 links.

Lastly, I still like the M-60. As Mark stated above, I too haven't had any real issues with mine. I have ran thousands and thousands of rounds through mine and the only issue I have had is a broken bolt cam (parts do break on EVERY weapon at some time). It chugs a long slow enough that you almost feel like you are hand-setting each round into the target. The thing I don't like about the M-60 is that it feels like am using an anemic jackhammer.


Adopt me, I'm really good a long hours of wpns maintenance...and keep those MG's busy...:D

karl johnson
06-25-2008, 07:21 PM
Because I know a thing or two about machine gunnery,

Probably more than I do, frankly. Still, some designs are worth more than the sum of their parts.

I whacked a mortar crew at about 800 meters with a PKM, so I'm kinda sentimental.

AmericanWarrior
06-25-2008, 07:33 PM
Probably more than I do, frankly. Still, some designs are worth more than the sum of their parts.

Like I said in a more traditional machinegun role I'd chose the 240, I'm sure the PKM is extremely reliable as much as would be expected of any Russian made wpn


I whacked a mortar crew at about 800 meters with a PKM, so I'm kinda sentimental.

Did they even see it coming? Tell me a little about it if you would? I didnt get to do much shooting past 400ish maybe 500 meters most of it was always pretty close.

thats way I would love to make a deplyment to Afghanistan, I could really put my skill with the machinegun to some good work!! And I think in that environment most would see a difference in the two designs.

LarryinAz
06-26-2008, 03:38 AM
MmmmmMmmmmMmmmm...I love me some PKM...




http://i73.photobucket.com/albums/i234/Biggame223/xUSMCpendPKM.jpg?t=1214472729



http://i73.photobucket.com/albums/i234/Biggame223/CmpLJ2.jpg?t=1214472865

http://i73.photobucket.com/albums/i234/Biggame223/ClassClean.jpg?t=1214472934

AmericanWarrior
06-26-2008, 11:12 AM
My company machinegunners got to do some really good and unique classes/range

Both were tought by civilians(MPRI..?? not sure)

The first was a three day range that covered everything in the world of specialized MG employment, it was some very advanced stuff...Much, much more then just direct lay at a few hundred meters...we worked at ranges exceeding 1200m+ and work every technique of fire pertaining to the MG's in general! Me and my AG fired about 8000rnds a day. The training should be the STANDARD but its not:rolleyes: ...

the other was two days of classes and one day on the range...it was a foreign wpns (machineguns - for the Co. gunners and rifles for the rest of the Co.) Out of the four other weapons the wpn you think most would/should have been there(the PKM) was not ... infact I only really remember the HK21E ... I thought I doubt I'll run into one of these but whatever...

DoctorCheney223
08-08-2008, 12:15 AM
Here is what you need for your CQB PKM's. Finished this one up today :D

http://img519.imageshack.us/img519/9811/shortpkmbbl2id0.jpg

thanks,
Ron

gunplumber
08-08-2008, 10:56 AM
Very nice - I've been considering that for the second barel - did you have to change the gas port sizes? If so, to what?

The other thing I'm trying to figure out is a minimum modification folder. The one I saw for the 7.62x51 NATO PKM folded up and to the right but the hinge was at the wrist - not the full length of the stock.

The plans I have for the PKMS (hMG-K) look like an AK 74 folding mechanism but I'd like to find a real one to copy before cutting my PKMs up and experimenting.

Gabe Suarez
08-08-2008, 11:25 AM
S.I. has access to a few PKM Machineguns...among other things. They will be seen in a couple of new DVDs very soon. And who knows...maybe even a two day ComBloc Weapons Operator class that doesn't take an entire week or cost the equivalent of a house payment.....:D

jlbraun
08-08-2008, 12:03 PM
Just as an aside, VLTOR is selling semi-auto PKMs:

http://www.vltor.com/project_pics.htm#Production%20models

They're $5500, but you get all this:

http://www.vltor.com/images/PKMsystemSmallw615x461.jpg

DoctorCheney223
08-08-2008, 12:21 PM
GP,

I had my guy shorten the barrel and we tried it with heavy ball "MG" ammo and it ran great. I need to go run it with some light ball and see how it runs. I want to avoid modifying the port size if we can make it run by adjusting the gas setting on the barrel instead. My guy is also making a block that will allow different stocks but I pulled him off of that until we get some more "real" work done (I am sure you understand that ;) ).

thanks,
Ron

S-Lee
08-19-2008, 12:52 PM
Speaking of Vltor, i was just at their tucson facility for a grand tour, here are some of the pictures involving the PKM.....

http://photos.imageevent.com/smglee/clt2/small/DSCN0331.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0331.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0332.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0332.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0333.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0333.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0335.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0335.jpg)

S-Lee
08-19-2008, 12:53 PM
http://photos.imageevent.com/smglee/clt2/small/DSCN0336.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0336.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0337.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0337.jpg)
Vltor made PKM receiver in the white and also compare to a build up Vltor receiver with all internals.

http://photos.imageevent.com/smglee/clt2/small/DSCN0338.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0338.jpg)
Vltor PKM with Russian kit... it is actually a very light weight GPMG compare to other NATO spec versions.

http://photos.imageevent.com/smglee/clt2/small/DSCN0339.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0339.jpg)

S-Lee
08-19-2008, 12:54 PM
http://photos.imageevent.com/smglee/clt2/small/DSCN0340.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0340.jpg)
Close up of the receiver.

http://photos.imageevent.com/smglee/clt2/small/DSCN0341.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0341.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0342.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0342.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0343.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0343.jpg)

S-Lee
08-19-2008, 12:55 PM
http://photos.imageevent.com/smglee/clt2/small/DSCN0344.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0344.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0345.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0345.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0346.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0346.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0347.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0347.jpg)

S-Lee
08-19-2008, 12:56 PM
http://photos.imageevent.com/smglee/clt2/small/DSCN0348.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0348.jpg)

http://photos.imageevent.com/smglee/clt2/small/DSCN0349.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0349.jpg)
simple reverse AK gas design...with pivoting gas piston for ease of installations and a flowing firing pin.

http://photos.imageevent.com/smglee/clt2/small/DSCN0354.jpg (http://photos.imageevent.com/smglee/clt2/huge/DSCN0354.jpg)
compare to the latest FN MK46, the PKM is actually a lighter platform.

LMGBeliever
08-19-2008, 07:25 PM
The PKM's greatest weakness is the non disintegrating belt. With a couple rails and a disintegrating belt, it would have no rival. 7.62x51mm would be preferred (for US use), but even without all that the PKM is a great MG.

Dale Hunter
08-20-2008, 11:17 AM
IIRC, they used a non-disintigrating belt for a couple of reasons: one, resupply from rear units could be a while and one might have to reuse the same belt,(yes you can do the same with disintigrating belts, but which is easier & faster?). Also, it would be extremely difficult to recover MG links out of a Siberian snow drift unless they were all one piece.

mlhoward
09-16-2008, 01:12 PM
For a short while, DSA offered a 7.62x51 version. I wonder who made it, and if it used NATO disintegrating links?

gunplumber
09-18-2008, 11:18 AM
For a short while, DSA offered a 7.62x51 version. I wonder who made it, and if it used NATO disintegrating links?

Are you sure you're not thinking of the FN MAGs (MAG 1958) they had?

The only 7.62x51 I know of is a prototype - picture in last Month's SAR. side folding stock and uses M13 links.

mlhoward
09-18-2008, 03:51 PM
Are you sure you're not thinking of the FN MAGs (MAG 1958) they had?

The only 7.62x51 I know of is a prototype - picture in last Month's SAR. side folding stock and uses M13 links.Pretty darn sure it was PKM or variant. Maybe the Polish ZM Tarnow UKM-2000? I guess I could email them.

LarryinAz
09-23-2008, 07:17 PM
For a short while, DSA offered a 7.62x51 version. I wonder who made it, and if it used NATO disintegrating links?


They are Bulgarian IIRC...

gunplumber
08-03-2010, 10:08 AM
The PKM that took M13 links was displayed at a European Arms Show and had a small picture in SAR. They wouldn't let Dan Shea open the top cover or take any closeups. The folding stock went to the right and up at 30? degree angle when folded.

TTBOMK that is the only one in 7.62 or with disintegrating links and is a prototype.

KMFDM
08-03-2010, 11:13 AM
The Arsenal PKM 7.62 NATO variant is nothing new folks, it has been around for awhile. I think I still have some of the company literature from Arsenal from my visit there in 2005 that shows one in 7.62 NATO. How many have they made I don't know though? DSA had one for sale some time back that was a dealer sample if I remember it correctly, I remember callling and talking to one of their reps about it.

As for the links disintegrating links are more expensive, and there always are a few guys around to stuff ammo in belts in a military unit. They save alot of money by not making all their ammo on these links. The German army still uses non disintegrating belts as do a few others. As it goes (my guess is) cost is probably one of the biggest considerations.

gunplumber
08-03-2010, 11:25 AM
Do you have a link to this?

My research only shows the Polish HCP PKM NATO. The prototype was tested from 1997 to 1999, but was rejected. This took the M13 links.

The Polish Army adopted the UKM-2000 instead which is in 7.62 NATO and also based on the PKM. The only images I've found were without the belt so I don't know if they take the M13 links.

http://blogimg.goo.ne.jp/user_image/0b/84/4bfd2fb2762d54e1ec298438c8ae4d83.jpg

The bulgarian 7.62 NATO MG-M1 is based on the PKM but doesn't use the M13 disintegrating links

http://www.arsenal-bg.com/images/defense_police/7,62x51mg-m1.jpg

gunplumber
08-09-2010, 12:32 PM
There are two basic feed systems for a belt-fed machinegun.

on a PUSH FEED system, the link holds the cartridge case from the rear, usually by the extractor recess. The bolt pushes the cartridge forward through the link and into the chamber. Examples are the MG34/42, M60, M240/9. RPD.

on a PULL FEED the link holds the cartridge case from the front, usually by shoulder. The mechanism pulls the cartridge to the rear, out of the link, then moves it up or down before going forward into the chamber. Examples are the 1919, M2, PKM, Vickers, etc.

You can't do a push feed using a link that holds the case from the shoulder (can't push the larger case through the smaller link) and you can't do a push feed with a rimmed cartridge (can't push the rim through the link).

You can do a pull feed on a rimless cartridge (1919) but you can't do a push feed on a rimmed cartridge (at least I know of no such example). On the 1919, it is a rimless cartridge and a pull feed, but it still uses the front-hold belt. That's why the 1919 converted well to 7.62x54, .303, 7.65 Argentine, 7.62 NATO, .30-06, 8mm, etc. The belt held the case by the shoulder and the extractor groove (rimmed or rimless) held the case on the bolt as it was pushed down to the chamber. The PKM has a 2-claw retractor, and a spring lever on the top cover to angle the round down for feeding.

There are conversions of pull-feed using the rear-hold M13 link - the Canadians modified a 1919 to do this, but I haven't seen how it works.

Because the the PKM is pull-feed from a front-hold link for a rimmed cartridge, I suspect it would be a significant redesign to make it feed a rimless case from a M13 link. While it can be pulled with a smaller retractor, it doesn't have lateral support like the 1919. Perhaps significant enough that it could no longer be called a PKM, even if it shares basic design principles.

In any case, I'd love to see pictures of the mechanism.

BKern
08-09-2010, 09:53 PM
There is one 7.62x54R caliber machinegun which uses a push through belt. The Czech UK Vz.59.

http://world.guns.ru/machine/mg28-e.htm

gunplumber
08-10-2010, 08:54 AM
Interesting. The ramp on the link acts against the rim to makes the cartridge wedge off the link. It is not a straight-through push, so maybe this should be considered a 3rd type?


Btw, looking for mags and belts for the Vz52/57

Coolhand77
08-10-2010, 10:24 AM
Hmmm, I wonder if you could take Kel-tec's RFB design, and reverse the load/eject sequence to make a better "Pull" mechanism...
Sorry, just thinking out loud

LarryinAz
08-11-2010, 03:12 AM
Getting ready for class...


http://i35.tinypic.com/2z9b94x.jpg

w8lftr
12-07-2010, 02:31 PM
Neat picture of the lined up PKM's; I'll bet class was fun.

SPQR476
12-08-2010, 07:00 AM
I love the 240B, no doubt about it...way more controllable IMHO. PKM has it in complete crappy condition reliability, but only by belt issues. The only 240 stoppages I've ever suffered were due to trying to use the same belt for too long exposing it to dust and then blowing it out with compressed air. Friction became too much to de-link the ammo and would stop up the works. A really dusty NEW belt would run just fine, but if you weren't seeing any action, hanging on to the same belt might cause a guy problems. I don't like the non-desintegrating belt and RtL feed of the PKM, and it's a little light, but it works pretty much no matter what.