A Discussion Of Machine Guns Used In/On AFVs
   (Ver 2)


I'm not exactly sure what message I was replying to when I wrote this but it lead to the following discussion of machine guns. (Please note that these are my opinions, based on 16 years in the military, and may have no foundation in fact.):

On second thought, is this about the article I did on machine guns? I had the nomenclatures all wrong in that article. The early coax for tanks, while I was in, was the M-73. It was a real piece of junk, and theoretically gas operated. The barrels were fairly easy to change, but I never saw one fire enough rounds for the barrel to get hot. The receiver group was basically a riveted metal box with a removable cover. An added value feature is that it could accept ammunition feed from either side. The removable cover was held on by two pins that were easy to drop and almost impossible to put back in with the weapon mounted. It was not designed for any use other than as a coax. As a matter of fact, the barrel jacket was semi-permanently mounted in the gun mantlet. The early versions had a set of rectangular metal rods more than a foot long, and unsupported except where they were welded to the rest of the barrel jacket, for a flash suppressor(?). Naturally, they got stepped on a lot with spectacular and unpredictable results the next time the gun was able to get a round off.

It fired from the open bolt position and, during assembly or disassembly, and especially during stoppage procedures, it was rare to get away without having the extractor try to eat at least one of your fingers. Another big drawback was that the solenoid that released the sear was not well sealed. All too often people would drop them into the parts cleaning tank with the rest of the gun, and they soon reached a point where the only time they worked was when you were trying to show the armorer that they didn't work.

There were two handles mounted to the receiver on the ends of chains. On the right side was the charging handle and on the left was the manual trigger. The normal mode of operation was for the loader to charge the weapon then pull the manual trigger (because the solenoid wasn't working). Normally this lead to the firing of one round due to feed problems or some other mysterious internal problem. If the loader was lucky, the bolt cycled before it jammed. If the extremely poorly designed gas operating system wasn't working, which was the normal situation, the loader would have to charge the weapon again. Due to the design of the extractor, it was extremely common for the base of the cartridge to be pulled off with the rest of the cartridge still in the barrel even if the barrel was kept spotless (I know from experience). This required that the receiver be removed from the barrel, and the barrel be removed from the barrel jacket before the special tool for removing cartridge cases, which was not designed for use with the M-73, could be used.

The M-73 was replaced, in first line units, by the M-219 after some of the M-73's shortcomings were recognized. Apparently the manufacturer decided that, rather than re-design the gun, they would find ways to make it cheaper to manufacture so that it would cost less to replace ones that went irretrievably bad. There were no noticeable differences between the M-73 and the M-219 in the areas of reliability or ease of use. In appearance the M-219 looked like a cheap version of the M-73. This is the same principle as the difference between the German WWII machine guns, the MG-34(?), probably one of the best machine guns ever made, and the MG-42, except that the MG-42 was more reliable as well as being easier and less expensive to make. The M-60 machine gun, by the way, was based very closely on the MG-42 design.

Since you mentioned this I seem to remember that the Leopard Is used a modern version of the MG-42, which I think was renamed the MG-1 after conversion from 7.92mm to 7.62mm. I think that the stock was removed while it was in the vehicle but just needed to be snapped back on when it was removed. I seem to remember thinking, "What a remarkable concept! Wouldn't it be great to have one of those if your tank was disabled and you were on foot?" Even the Belgian coax didn't have any organic sights, tripod or bipod, and I don't think that the M-73/M-219 could even be fired outside the tank without disassembling the mount and removing the barrel jacket from the vehicle.

Sometime during my tour in Germany, probably in late 1978, we received the new Belgian coaxes. I'm not sure that they even had an 'M-' number at the time and we just called them 'MAG's. I think they were M-240s or M-248s but I don't remember. I only cleaned one a few times, so I don't remember much about the design. It was the standard box with a barrel design, like our other coaxes, and of no use outside the vehicle, but it was obviously well made. Everyone I ever saw fired perfectly, every time, and for as long as you wanted to press the trigger. One of our boneheads fired a 1,000 round burst from one and it just turned the barrel a dull red until it cooled off. When we tried it again about half an hour later, it still worked perfectly. Frequent cleanings didn't seem to be required in order to keep them reliable. Some TCs went through the entire gunnery qualification cycle without cleaning theirs. They were awesome.

As I said in the article, the M-73/M-219 ruined a generation of gunners. With them, even though the gunners knew that they weren't controlling the firing of the coax, they were trained to keep the trigger pressed until given the command to 'cease fire'. With the new coaxes the loader's quickly learned that, after chambering the first round, they weren't needed any more in that part of the turret. There weren't even any ammo feeding problems, partly because the retro-fit involved a new and much less agricultural looking mount for the coax. So the gunners would just sit there with the trigger pulled and wonder why the gun was still firing at all and especially why the loader was firing continuously instead of 15 round (3 tracer) bursts. It just seemed to take a long time for it to sink in that they were in control and the loader was sitting in his seat wondering what was going on.

At this point Eric said:

Dont know if I replied to this but its not about any article you did. We used 30 brownings on centurions as coax and 50 brownings as ranging guns and 30 brownings on ferrets (mk5 ferrets had a gpmg)and saracens. We used what we called GPMGs on most other vehicles. That I think was what you called a MAG. It was pretty good as either a coax or squad weapon.

My reply to Eric was:

You say a '30 Browning', but there were a number of varieties, and this is getting pretty interesting because of the mention of a standard 'Browning' mount, which I had never heard of. I think that the last Browning automatic weapon that the US forces used was the BAR (Browning Automatic Rifle, 20 shot mag and capable of full automatic fire, not mountable, but with bi-pod) during Vietnam, but only by special units, and only during the early 60s. (OOOps, the M2-HB .50 caliber was a Browning design and is still in use.) When I went through my first weapons training in the late 60s some of the instructors talked about experiences with 30 cal Browning heavy and light machine guns (water/urine cooled or not water cooled), but I never saw one. The M-60 was firmly established by then.

Most US tanks have a .50 machinegun for the TC, and it can be used to designate targets, but we were told that its primary function was anti-aircraft, which doesn't make a whole lot of sense. The M-47/M-60 series had the M-85, and I have no idea who made it. The Sheridans and most other light vehicles, even including trucks, had the Browning M2-HB. I've heard that the Abrams also uses the M2-HB. (Nice weapon. Absolutely indestructible but very heavy and with a low rate of fire.)

Your next statement is what puzzles me. The MAG that we had could not be converted for use outside the vehicle. It had no sights, no equipment for ground mounting, and a significant amount of it was even painted white. I think we are talking about two different weapons.

I don't remember Eric's reply to this.

From Dale,

I may be able to clarify some details about the machine gun fitted to the Leopard 1.
I gun itself is called the MG 3 not MG1. Rory is correct in saying the MG3 is a modern version of the MG42. The germans were onto a good thing with the MG42 as the only things that were changed to turn it into an MG3 were as follows and the reasons for the change

1. Cocking Handle. Was changed from a fixed metal handle to an articulated item so that it would fit into the co ax mount of a Leopard 1. If it wasn't you would certainly given more blood to the gun gods. I have heard stories that the MG3's used by the german infantry still retained the fixed handle.

2. The calibre was changed from 7.92mm which at the time was the standard german military calibre to the NATO 7.62mm for obvious reasons.

3. Flash Supressor. Due to the change of calibre and more modern propellant the supressor was made smaller. I will try and explain why bear with me. The MG3 as was the MG42 is Gas assisted in operation. When the round is fired and leaves the end of the barrel the gas pressure behind it pushes on the flash supressor. The supressor is designed to focus a certain amount of gas onto the face of the barrel guide sleeve. The guide sleeve is a small alloy insert that the end of the barrel sits in directly behind the supressor. When this pressure pushes on the guide sleeve, which pushes the barrel rearwards which in turn unlocks the SA cams on the bolt which in the firing position are locked onto the barrel chamber. This pressure allows the barrel to assist in pushing the bolt rearwards to continue firing. Because of this the supressor had to be changed to allow the different gas pressure to assist in operation.

It's very hard to explain without having a gun in front of you.

I've fired and qualified on the MG3, M60,Minimi, M240, MAG 58 (M240 in the ground mode), 50cal, 30cal and just about every other bullet chucker in the armies inventory. I can honeslty say that the MG 3 is without a doubt the best machine gun I've ever had the pleasure to fire. It's reliable a buggery, has an amazing rate of fire 1300 to 1500 rounds a minute which if I'm not mistaken is the fastest firing single barrelled machine gun in service world wide, you can change a barrel in seconds (good thing when your firing this fast)and is easy to use. I'll digress for a little while and regale you with a short story.

In 1992 my troop was tasked to go out to the range and assist a company of Malaysian infantry in a live fire exercise. We were informed that they would supply all the ammunition for this exercise. When we hear this it normally means a few hundred rounds. Well! We were sorely mistaken. On arriving on the range we were confronted with 27,000 rounds all for us. If you thought that made the boys eyes light up your right. So we have 27,00 round 3 tanks, and 3 live fire attacks and we only brought 1 MG3 per tank and no extra barrels. That equels 3000 round per tank for an attack of about 500 metres and we were told they didn't want any rounds handed back. At the time I was loading. We were shooting 300 to 400 round bursts if you could call them bursts. There was no let up and by the end of the first attack the barrel was white hot and burst into flames which was a bit disconcerting with 9000 rounds stowed below the gun. At the end of each run we had to take the guns out of their mounts, put them on the rear engine deck fan and rev the hell out of the engines to get the large cooling fan above the radiators to start spinning which in turn sucked cool air over the guns. We couldn't spray any oil on the guns before this as it just burst into flames at every opportunity.

Throughout the whole ex we didn't have a single stoppage. Now that's a gun.

Well back to the discussion.

Out of all the GPMG's I've fired they all seem to have a direct link to the MG34, 42. All of the feed mechanisms are basically the same. I guess when your onto a good thing stick to it.



My thanks yet again to Rory, Eric and Dale.


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