Continuous Fire for MG's

[CRMichaelis]

Something came up at the last battle and I'd like to explore it a bit. There was some contradicting views floating around regarding how much an MG should be firing to be authentic. Some argued that short bursts are correct to keep the barrel from overheating, others contended that being water cooled that would not be an issue. So let's discuss!

Here is a quote from Wikipedia regarding continuous firing by those fine Vickers guns at the Somme:

The weapon had a reputation for great solidity and reliability. Ian V. Hogg, in Weapons & War Machines, describes an action that took place in August, 1916, during which the British Army's 100th Company of the Machine Gun Corps fired their ten Vickers guns continuously for twelve hours. They fired a million rounds between them, using 100 new barrels, without a single breakdown. "It was this absolute foolproof reliability which endeared the Vickers to every British soldier who ever fired one."

So being the accountant that I am I did some calculating. One million rounds fired by 10 guns equals 100,000 rounds fired per gun. Divide that by 12 hours and you get 8,333.33 rounds per gun per hour. Divide this by 60 minutes and you get 138.89 rounds per gun per minute. Divide this by 60 seconds and you get 2.31 rounds per gun per second - for 12 hours! Taking time out to feed a new belt, filling up water jackets, replacing barrels, etc., and it seems to me that you had some fairly continuous firing. Each gun would have fired off 4,000 belts (333.33 belts an hour, 5.56 belts per minute) and used 10 barrels each (.83 barrels per hour).

All this lends credence, in my mind, to the guns being fired almost continually. The obvious limitation to a burst would be 250 rounds and then changing a belt. To me that means long bursts are not necessarily unauthentic for a Vickers, Browning, Schwarzlose or Maxim.

Thoughts, comments?

[Larry Dunn]

Hmmm, interesting. How shall I put this... I take anything Ian Hogg says with a grain (make that a chunk) of salt. Even so, with a rate of fire of around 500 rounds p/m, that's 8.33 rounds per second, so each gun would only need to fire 16-17 seconds each minute, slightly more than 1/4 of the time. Let's say a crew spends half their time with belt, water and barrel changes--they'd still only need to be firing around half of their "on-line" time to expend that much ammunition. I would think that short but frequent bursts would be the most likely modus operandi.

-Larry

[CRMichaelis]

Yes, I'm already finding out quickly that Mr. Hogg might tend to "round up" his figures. Here is another article regarding the same action:

On 24 August one of the most celebrated machine gun actions of all time took place nearby. This was the famous barrage fired by 100th Machine Gun Company in support of the capture of High Wood. With the assistance of two companies of infantry to do the fetching and carrying, rapid fire (officially laid down as 250–300 rounds per minute) by 10 guns was maintained continuously for twelve hours. At the end of this period they had fired 900,750 rounds. Their target was the area behind the crest-line on which High Wood stands, through which German infantry attempting to counter-attack had to pass. According to a German prisoner, the effect of the machine-gun fire was ‘annihilating'. This barrage was of course rather out of the ordinary, both in terms of its duration and in the lavish expenditure of ammunition. Nevertheless, along with the preceding examples, it shows that by the late summer of 1916 the use of machine guns in the British army was showing signs of increasing sophistication.

This is taken from a good article on British use of the MG:

British Machine Gun Tactics on the Western Front 1915–18 by Paul Cornish

www.essentialsomme.com/articles/british_machine_gun_tactics.htm

This states (and maybe Seph or Phil H can add in on this) that "rapid fire" was 250-300 rounds per minute - a little more than half the maximum rounds per minute for the guns.

Don't want to split hairs, but I think it would be interesting to know how much we should be firing and for how long.

[rsm2ndbtnlf]

A good point your raising there Chris. Let me give from my own personal experiance.

When taught the Bren LMG, GPMG, and Vickers... we were shown how not to fire, type of bursts required, type of bursts effective, etc.

Barrel changes were the first priority in order to keep the Bren and GPMG operating to maximun efficiency, whilst water supply for the Barrel Jacket was the main priority for the Vickers.

So.. what do we decern from this? Basically put, it all comes down to the time it takes to fire off a certain amount of ammunition : without releasing the trigger = Rapid or Sustained Fire. In order to clarify this point, we need to know what each state of fire means.
1) Rapid Fire = The greatest amount of ammunition the weapon (within it's specific operating parameters) can fire onto the target in order to control, hamper or destroy an enemy, without destroying ones own weapon in the process, and thus endanger ones own troops.
2) Sustained Fire = Enough weight of ammunition fired at an enemy to stop or control his actions whilst a Friendly Force is in assault.

Taking the above into account, what do we know of the three Machine Guns I mentioned?
1) Bren LMG (Light Machine Gun) = Section Assault Weapon, fed by a 32.rd gravity fed Box Magazine, with Quick Change Barrel (Air cooled).
2) GPMG (General Purpose Machine Gun) = Section Assault Weapon, fed by a belt of Disintergrating Link ammunition of no decernable size =(x1 round with x1 disintergrating interlocked link), with Quick Change Barrel (Air cooled).
3) Vickers HMG (Heavy Machine Gun) = Company Defensive Weapon, fed by x250rd canvas ammunition belt, with a fixed barrel (water cooled).

The Bren, given its fairly slow rate of fire, even when operating in the rapid fire roll, could sustain quite lengthy periods before the gunner was required to change the barrel = x1,000rds.

The GPMG however was a different measure, with a much higher rate of fire which, if required, could be made continious by the amount of ammunition clipped together. A continious fire of x500rds was recommended before a barrel change in this circomstance, or x1,000rds in normal fire usage.

The Vickers is a world apart from the two former, it being a defensive weapon and water cooled. Contrary to popular belief, the water in the jacket will boil out very quickly... much quicker than anticipated... if the weapon is used for continious rapid fire missions.

For the Bren and GPMG, the gunner was advised never to let the barrel become WHITE-HOT, as this very quickly destroys it. Once the barrel begins to glow.... a dull orange, that is the time to pause for a few seconds between bursts. A gunner for either of the two above weapons only carries three interchangable barrels = one on the weapon, and x2 in the spares satchel.

The Vickers gunner is at a distinct disadvantage, in that he has a superb defensive weapon with an Achilies-Heal..... it requires water to operate efficiently! The gunner cannot see the barrel if it reaches the white-hot danger level, but knows when to slow the rate down by the preasure released from the barrel jacket as STEAM. It is recommended that a burst of between x100 to x150rds for Rapid Fire. Bursts of x50rds are the recommended rate for Sustained Fire operations, with a burst of x20 to x50 for normal rate of fire.

What must be understood is the difference is usage of the two rates of fire : Rapid and Sustained.
1) Rapid Fire = Maximum effect for a short period of time (eg: The Mad Minute). The wapon is being used to it's maximum as a Hammer Punch... in order for friendly forces to gain control of the situation.
2) Sustained Fire = The weapon is being used as it was designed to be used, but over a greater period of time. In order to do this, the weapons cyclic/max rate of fire is slowed.

The above are only recommendations gleamed from my own personal experiances, and are not to be taken as a 'Must Do' from any period weapons or instruction manuals. The above information has been given freely as a guide to help decern future usage of similar weapons used by the GWHS during Trench Events, in the hope that ammunition usage can be determined.

[CRMichaelis]

Seph,

That's the info I was hoping to find. While not "historical" in a WWI sense, it is practical, actual military experience that we can adopt for our use.

From your numbers the timing of the bursts required would be as follows:

Burst/Seconds
150 rounds/18 seconds
100 rds/12 sec
50 rds/6 sec
20 rds/2.4 sec

This is assuming a cyclic rate of 500 rounds per minute. So this refutes my first assumption, and backs up Larry's contention.

Good stuff. Thanks!

[rsm2ndbtnlf]

Glad I could help! ;D

[Larry Dunn]

Great information, thanks Seph! (And thanks to Chris for doing the math).
Just to summarize, it would seem that 3 to 5-second bursts would be the norm, with 10 to 20-second bursts in situation where "rapid fire" is required--with the understanding that this can only be sustained for a short period of time.

-Larry

[oskar2ndchev]

From my Army experience, we were taught to the fire the M-60 Machinegun (it's simliar to the GPMG that Seph mentions abouve) in bursts and as a quick memory device, we would fire while saying "fire a burst of three" and then letting off the trigger.

I think something like that would be useful in firing the gas guns, thereby slowing down the rate of fire. Also, performance on a range can be very different than out in the field in a combat situation (or simulated combat situation).

Finally, while I'm sure we can all prove up some pretty extreme examples of sustained MG fire, for the purposes of our battles we need to arrive at some sort of happy medium to keep things reasonable for all concerned.

[Radford]

1) Bren LMG (Light Machine Gun) = Section Assault Weapon, fed by a 32.rd gravity fed Box Magazine, with Quick Change Barrel (Air cooled).

Dear Seph and List-

Please don't confuse "top fed" with "gravity fed". A Bren Gun magazine has a bloody great spring in it which helps push the bullets out the open end. Bren Gun magazines were typically loaded to "only 27-28 rounds to reduce strain on the magazine spring and thus ensure reliability of the feed under harsh conditions" (World Guns article). A gravity fed weapon such as a Gatling Gun has loose rounds in hopper or magazine which simply fall under their own weight into the feed mechanism.

As for being an "Assault weapon", I once worked with a man who had been a Commando in WW2. He was on the Dieppe raid. His entire rifle section was armed with Bren Guns - they were using them as assault weapons!

Cheers!

Radford

[rsm2ndbtnlf]

I see that someone is having diffuculty in decerning the difference between the weapons feed system position, and the ammunition feed method used! Don't be afraid to ask a question if one is not certain!

OK... lets be techknical shall we?
1) Bren Magazine... Curved, to allow for the seating of the .303.inch ammunition. Built in a box structure, so known as a "Box Magazine". Yes, there is a huge internal spring in the magazine, but a little one would not be sufficient to carry out the designed task!

2) No mention was made of the Brens ammunition feed position = TOP FEED. HOWEVER, mention was made of the ammunition feed source = A 32rd Box Magazine = Gravity Feed {x32rds being the officially quoted term for the maximum capacity of the magazine], IE.... the magazine is placed on the weapon upside down, thus, the internal magazine spring does not force the rounds up in readiness to be fed into the chamber, but assists in seating the round in place during its downward travel = Gravity Feed. Due to the Bren Magazine Spring being weaker than a force feed magazine spring = Feeds upwards - not down... to use it in the normal fashon, = rounds uppermost, would result in frequent weapon ammunition feed jams (Actual Combat Usage).

3) Unlike the weapon you quoted = 19th Century Gatling Gun, the ammunition in the Bren Magazine is STAGGARD, not one behind the other. Therefore, in order to seat the rounds correctly a platfom is required to hold the rounds in place. To keep the platform against the rounds, a spring of concertina design is used.

Those of use who have experianced Military Service would automatically know this information, but we do not mind educating and correcting those who have not been so fortunate as ourselves!

;D ;D ;D

[Radford]

Those of use who have experianced Military Service would automatically know this information, but we do not mind educating and correcting those who have not been so fortunate as ourselves!

Dear Seph and List-

Thank you for the education! I looked around on the internet and saw that a couple of other ex-British service men described the box magazine for the Bren as "gravity fed", so I stand corrected and do apologize.

Cheers!

Radford