"Coaxial Machine Guns - National Differences" Topic

Japanese tanks had magazines I believe.

Seems like a pretty fine distinction to bother modeling.
-Kle.

This thread got me thinking. The rules I use, 'Arc of Fire', significantly downgrade AFV co-ax and hull MGs in relation to those carried by infantry. Is this correct?

There are visibility problems when buttoned up -- they may be modelling that.

Brit Besa's were belt-fed – but, to further complicate matters, the majority had selective rate-of-fire; 500rpm or 800rpm.

(Late war production models were either one or the other, for simplified manufacturing.)

From my experience with the NATO Bren during my service (many) years ago and later with the Browning, I would think a magazine is if anything, slightly faster to change as you don't have to open the breech like you do on the M1919 or German MG's.

It's worth noting that tank MG's don't do "sustained fire" anyway, because the barrel will overheat and you can't do a quick barrel change without dismounting the gun (one reason for the selective fire rate on the BESA)

Before the adaptation of the excellent FN GPMG as the M240 on US tanks, we had to somehow try to use the M219:

link

It was belt-fed, but prone to jam… no! "Prone to" is not exactly correct; "guaranteed to jam whenever the gunner pressed the firing stud" would be more accurate.

If you wanted to get any points for coax engagements during annual gunnery (rather than zero points due to time, while the loader attempted to unjam the weapon), your loader needed to be prepared to manually guide the linked rounds into the weapon with one hand, while constantly pouring oil on them with the other hand. Not really practical in combat.

Changing to an extremely reliable coax in the M240 was met with great rejoicing, even though we knew we were riding in deathtraps in the M60 series.

Allen

DT MG which was the coax on many, if not all of these tanks was the same disk magazine fed LMG the ground troops used

It depends what you mean by the same. While it's the same mechanism there are detail differences. The most obvious being that the DT used a 60 round double layer pan compared the to 47 round single layer used on the DP.

Confusion does arise because many DTs were issued to the infantry in lieu of DPs. Where they proved popular due to the larger capacity but smaller diameter pan compared to the 'record player'. It's marginally heavier but IMO actually feels a bit 'handier' because of the smaller pan. Sticks up a hell of a way on the bipod though.

DP picture

DT picture

why would you be doing sustained fire with the coax? it would be a pretty inefficient way of shooting at something when you have to point the main gun at a target. weren't they more for ranging?

<<It was belt-fed, but prone to jam… no! "Prone to" is not exactly correct; "guaranteed to jam whenever the gunner pressed the firing stud" would be more accurate.>>

You could do better with the M219 if you threw it down range.

<<weren't they more for ranging?>>

Primary purpose was intended to be for ranging as mg rounds are cheaper than a main gun round.

Well… a ranging machinegun, as in WWII, was one thing. But a coax is primarily for anti-personnel and anti-materiel. Once you get beyond the technology of a reticle (choke) rangefinder, and start accepting input from a stadiametric or laser rangefinder, not only does the coax become a less efficient ranging method, but you're likely to be using different sights for the coax and main gun.

Or have I forgotten something in my old age?

Allen

I always figured the coaxial MG as a MMG (or HMG if you don't have a MMG category), and the hull MG as a LMG.

In addition to the advantages listed above, the coaxial has a steady platform and a telescopic sight.

Gotta admit the inability to quick-change the barrel would be a draw-back.

at first, i used to think like ditto t about coax mgs, until someone pointed the "changing barrel" question

The MG's used for ranging were just that, ranging MG's. The same ballistic properties as the main gun and only used for that purpose. Co-ax is something different.

Also, I'm not sure on thisthough, weren't ranging MG's a later idea then WWII?

I know the Cheiftan had one.

"The coax is meant for soft infantry targets, like you were, number4. grin"

Not guilty! I was a soft artillery target….if an enemy tank got within miles of us, something had gone very badly wrong :)

Yep, the M1919 doesn't have a quick barrel change, which is why the SF version is water cooled. Rate of fire though largely depends on the guy behind the trigger. AFIK the belts were all cloth in WWII; must have been unhelpful in the close confines of a Sherman!

The co-ax is definitely an anti-personnel weapon though – some early tanks had the MG as their only armament (think early T.26, Vickers, Matilda I, Panzer I, Italian light stuff). Even those armed with cannons fired only solid shot and relied on the MG for use against infantry.

The ranging MG on the Chieftain BTW was a .50 cal; this was replaced by a 7.62 when laser range finders made them obsolete

Also it is important to remember that tankers firing their machine guns aren't too worried about the return fire from small arms. In my opinion this allows them to spend more time aiming and shooting effectively. Just my experience though.

Leaving aside reliability issues of the mechanism itself sustained fire is more a function of barrel heating than it is of feed type. A Bren gun can be fired in an SFMG role given the right ancillary kit, clinometer, tripod etc etc.

As for the imparcticality of MGs as ranging aids, well that might be true of WW2 but pre-lasers and digitalisation, one of the most effective ranging systems in existence was the .50 ranging MG fitted to later mark Centurions. According to Kenneth Macksey, RARDE took a Centurion with this system to in the 1960s and trained up an American crew who then proceeded to do considerably better with the ranging MG system than they could with their own kit.

Also, I'm not sure on this, though, weren't ranging MG's a later idea then WWII?

I used to think that then I visited this restored bunker up near Opava.

link

The main armament is a Skoda 47mm with a ZB37 MG on top. Back then you could get a look through the sight and there's only one graticle. Also, just to the right there's a twin ZB37 covering, more or less, the same arc,.

I chewed over that for a while and the only explanation I can think of is a ranging MG. But I'm still not 100% sure because you'd have thought they'd have known all the ranges in their firing arc what with it being a fixed position.

Accuracy from a tank is much better. After all the coaxial is using optics and gun laying intsruments to assist in accuaracy.

In addition, the hull gunner, being protected behind armour, he is using tracer to assist his accuaracy. being behind armour inside a twenty-five to fifty ton tank, he doesn't really care too much that he may give his position away, so he may even be using belts with extra trace rounds above and beyond his one trace-four ball standard. Meanwhile the infantryman next trench over, will probably have removed the trace from his magazine or belt for fear of giving away his position.

While height gives better vision, the height of the weapon may not be as relevant as the ability to correct your fire by using the optics, gun laying instruments, trace and observation of the effects of fire. Light standing water allowed me to see bursts of coax out to 1700m watching the spalshes some 500m past trace burn out!

Don't confuse the idea of sustained fire. A tank carries a massive amount of mg ammo. Much better to drive your ammo about than to cary it on your back. This gives crewmen the ability to pour a lot more mg ammo onto a target that most infantryman could dream of.

Training in control of bursts helps to keep the weapon working, but so does training in weapon maintance and training in troubleshooting and replacement as a firing drill. I was trained by Korean war veterans. Part of the important drills they forced on to me was changing the barrel of the old Brwoning as a part of a firing drill. Bang, bang, click, go through your immediate action drill, it still fails, go through your stoppage drills, and if it still doesn't work, drop the back plate and change out the barrel, followed by reloading and continuing. This was all done to an expected time limit.

I later had the time to talk to a lot of tank vets. They all said they did the same thing, usually under fire. Those scars on their hands were earned.

Don't mean to mislead you Tim. I'm actually an SSM now for the last three years or so, but I just don't want to change my name. I miss the old Brownings,,, it was an art and a skill.

even though we knew we were riding in deathtraps in the M60 series.

On the "bright" side, most tanks of that era were in pretty much the same boat. Armor was not in ascendancy at the time. Centurion and Chieftain seem to have been better, but not by an order of magnitude or anything. The Soviet stuff seems to have proven to be explode-y since then. I don't really know how badly Leopard 1 or AMX-30 burn.
-Kle.

Number4

"The ranging MG on the Chieftain BTW was a .50 cal; this was replaced by a 7.62 when laser range finders made them obsolete"

The Chieftan had a co-ax 7.62 GPMG all the time.

Steve

Allen,
The best thing about the M219 was that you could take it apart and get it back together in 4 minutes, mainly because you often had to.
Tim,
Our rules don't differentiate between the coax weapons, but do for the ground mounted versions. Mainly you get a single light mg burst from the Coax, but multiple bursts from its ground mounted versions.
Weaselhoffen.

Also, we were never taught to range with the coax like WWII. It was use for targets tht you didn't want to waste a main gun round on, like troops in the open.
Weaselhoffen.