View Full Version : Indirect fire VS direct fire (M240, M2, M249, ETC. ETC.)
Draco771
11-17-2008, 20:32
Hello, I have a question on weapons, and figured why not ask the guys who are trained experts with weapons?
Recently I've been told that the M2 .50 Cal, and the M240 are indirect fire?:confused:
And I was curious as to why they are labeled as indirect fire, considering an M249 at an "arc" trajectory can hit targets at 1,000 Meters but is considered direct fire, same with various long range rifles etc...
Can some of you Quiet Professionals put in some insight?
The Reaper
11-17-2008, 20:35
Hello, I have a question on weapons, and figured why not ask the guys who are trained experts with weapons?
Recently I've been told that the M2 .50 Cal, and the M240 are indirect fire?:confused:
And I was curious as to why they are labeled as indirect fire, considering an M249 at an "arc" trajectory can hit targets at 1,000 Meters but is considered direct fire, same with various long range rifles etc...
Can some of you Quiet Professionals put in some insight?
Yep.
I believe that you have been misinformed.
TR
Draco771
11-17-2008, 20:38
Yep.
I believe that you have been misinformed.
TR
By a Field Artillery 1st Lieutenant, and two prior service too...:eek:
Oh wow... LOL (Lieutenant was busting my balls in another forum for me asking "Why is the M240 and M2 considered indirect fire" as well... wow... LOL The 1st Lieutenant was the one saying the M240 and M2 are indirect fire and I was asking him why)
Blitzzz (RIP)
11-17-2008, 20:43
All of these are direct fire. Not that you can't do "plunging" fire. Plunging fire is done with a direct fire weapon, but will normally be beyoud the max effective range of the round. ie. Ma duece out beyound 2500 meters, if you knew the right elevation you could "lobb" rounds in on troops over 4000 meters. You wouldn't get much feed back at that range but would likely get some heads down.
All of the a fore mentioned weapons fire center fire cartridges and are aimed...thus direct fire weapons.
Okay "plunging fire can be done but isn't the primary function.. Mortars are indirect fire. Blitz
Draco771
11-17-2008, 20:47
Thank you Blitz...
If only the Army taught Artillery Officers (Chem Officer branched Artillery) this kind of info...
On another forum I have a 1LT and two prior service dogging me for asking why they are saying the M240 and M2 are "Indirect Fire" as the 1LT said they were...
Thank you for the correct information, I appreciate it.
I'm not going to start an argument with info given to me on here, just going to leave it be on other forums, I just care about having the correct info for myself alone.
There is a mathmatical formula involed and you need a gunners quadrant.(I've only seen one once)
it's becoming a lost art.
From what I understand it was used extensively during the Korean War.
Draco771
11-17-2008, 22:48
There is a mathmatical formula involed and you need a gunners quadrant.(I've only seen one once)
it's becoming a lost art.
From what I understand it was used extensively during the Korean War.
What?
You mean they didn't do much of that during Vietnam?!?!?!?!?!?!?
I recall it being mentioned, but not directly taught, by the machine gun range cadre when I went through IOBC. It involves the use of the tripod and forward observer, and is used when the gun crew is in full defilade.
Yep, just checked an on-line version of what used to be FM 23-65, and para. 6.6 discusses defilade fire, where the gunner can't see the target and requires the assistance of an observer. As Blitzz mentioned, its referred to as plunging fire, not indirect fire.
All of these are direct fire. Not that you can't do "plunging" fire. Plunging fire is done with a direct fire weapon, but will normally be beyoud the max effective range of the round. ie. Ma duece out beyoun 2500 meters, if you knew the right elevation you could "lobb" rounds in on troops over 4000 meters. You wouldn't get much feed back at that range but would likely get some heads down.
Blitz
Manuals from WWI timeframe have extensive coverage of machine guns utilizing plunging fire. Massed, plunging fire. walking ahead of infantry. I remember thumbing through one at the Infantry School some time back. A google search also turns up quite a few references to MG's being used in this way during WWI
We were taught this in AIT at Ft. Ord in '68. It may have been because Ord was a bit lumpy and lent itself to that type of training. I thought it was called "raining fire" but I'm not sure.
More than likely the chatter of the Deuce would have been enough to keep the BG's heads down.
Pat
I saw one reference that discussed massed heavy machine gun fire being used in front of walking artillery barrages to attempt to catch enemy troops in the open as they unassed front-lline trenches in order to get out from under the worst of it. Also discussed using same in the interdiction role to prevent reinforcement and/or resupply of front line trenches. The below website has some histoical info on the British Machinegun Corps of WWI and references these tactics.
http://www.1914-1918.net/mgc.htm
blue02hd
11-18-2008, 06:06
I saw this in practice as a PVT in the RGR Bn. We were training in Yakima, and the plunging fire theory was actually tested with a company's compliment of 240's. I remember seeing the guns lined up and super elevated about 2 km's away from our obj that we built. I was in a line platoon, so I couldn't give you any more details on how they set it up. I will say that this was the one and only time I ever saw this, and for good reason. The ammo requirements were insane, the accuracy was very limited, and the effects on the target were minimal.
Kind of a neat story though, but not as cool as the Chechyans using RPG's in plunging fire mode against the Russians at Grozny.
Anyhow,,,,,
During the weapons course we were taught Plunging fire and taught the Gunners quadrant. They are rare but we did training on the range with one part of the class as FO's and they rest of us a gunners with the M2. We also used plotting boards to plot the fire for the M2's. It was amazing all the things that they crammed into the training and ranges.
Peregrino
11-18-2008, 07:54
Direct fire is LOS (line of sight), indirect is non-LOS. FA & mortars in direct lay are just as much "direct fire" as a rifle is. MGs in indirect fire haven't been much more than an academic footnote since WWI. abc_123 hits the nail on the head. (Not bad for an "O". :p)
Direct fire is LOS (line of sight), indirect is non-LOS. FA & mortars in direct lay are just as much "direct fire" as a rifle is. MGs in indirect fire haven't been much more than an academic footnote since WWI. abc_123 hits the nail on the head. (Not bad for an "O". :p)
I think the issue is the amount of massing that would need to take place, and the mountain of ammo that would take. The lack of true Lightweight MGs (or tactical fighting vehicles to carry the heavy MGs) made this the only way to employ heavy MGs in the offensive role. Not to mention that the geometry of the battlefield of WWI is what allowed this technique to have whaterver degree of effectiveness that it did.
Not sure how effective it was (google anyone??) but this technique was referenced as being used as late as 1917...
In mobile warfare... it is far more effective (and supportable) for MGs to be dispersed throughout maneuvering units rather than consolidated into companies and battalions.
Team Sergeant
11-18-2008, 09:38
Hello, I have a question on weapons, and figured why not ask the guys who are trained experts with weapons?
Recently I've been told that the M2 .50 Cal, and the M240 are indirect fire?:confused:
And I was curious as to why they are labeled as indirect fire, considering an M249 at an "arc" trajectory can hit targets at 1,000 Meters but is considered direct fire, same with various long range rifles etc...
Can some of you Quiet Professionals put in some insight?
Next time you ask us a question your fingers better be bleeding from all the typing you've done searching for the answer yourself.
You could have easily found your own answer concerning the above question.
http://www.globalsecurity.org/military/library/policy/army/fm/3-22-68/c05.htm#sectioni
Next time consult the FM before you ask stupid questions.
Team Sergeant
The Reaper
11-18-2008, 10:00
I saw this in practice as a PVT in the RGR Bn. We were training in Yakima, and the plunging fire theory was actually tested with a company's compliment of 240's. I remember seeing the guns lined up and super elevated about 2 km's away from our obj that we built. I was in a line platoon, so I couldn't give you any more details on how they set it up. I will say that this was the one and only time I ever saw this, and for good reason. The ammo requirements were insane, the accuracy was very limited, and the effects on the target were minimal.
Kind of a neat story though, but not as cool as the Chechyans using RPG's in plunging fire mode against the Russians at Grozny.
Anyhow,,,,,
Works a lot better with MG battalions and companies with semi-permanently emplaced, water-cooled guns using 250 round belts. Steel rain.
Not sure how you can use RPGs like that, since all of the ones I have seen had a self-destruct feature that detonates them at around 1,000 meters.
TR
I learned the basics of it in Advanced Machine Gunners School using .50 cals.
It is very difficult to set up and have effects on target within a short period of time.
A normal section of six 240's, in the offensive role, will be hard pressed to have effects on target before ammo requirements become an issue.
The only advantage to indirect fire is that the support by fire can be in full or partial defilade.
In the defense it may be useful, but only if there is the time and means to preregister the targets. Terrain and amount of guns permitting.
Draco771
11-18-2008, 13:39
Thank you everyone for your answers, and the information, personally I think that'd be pretty cool to see a line of Machine Guns bursting down like that... That'd be insane to be going into a field, and all of a sudden have Machine Gun fire coming down on you out of nowhere... I can't imagine what that would be like...
LOL
blueO2hd 2/75? (right on!)
and Team Sergeant, I personally didn't think to look into the Machine Gun FM... (Because at that point in time, I was going for human sources who have greater expertise and experience then a "book" because of a Lieutenants remark of them not being direct fire weapons) personally I didn't even know it existed until last night.
I greatly appreciate all of the input you QPs have put down, thank you.
abc_123 hits the nail on the head. (Not bad for an "O". :p)
Thank you.
:lifter
Team Sergeant
11-18-2008, 19:47
and Team Sergeant, I personally didn't think to look into the Machine Gun FM... (Because at that point in time, I was going for human sources who have greater expertise and experience then a "book" because of a Lieutenants remark of them not being direct fire weapons) personally I didn't even know it existed until last night.
I greatly appreciate all of the input you QPs have put down, thank you.
That "book" (FM) is written by former soldiers and is the very book I learned from......
There was a VC or NVA RR crew that used to zip a few rounds into camp indirectly from out in the bush.
They managed to kill some people.
Made a hell of a noise incoming, but very fast and hard to duck.
Doubt if the method was in any manual.
Noslack71
11-19-2008, 20:14
I recall the term "beaten zone or beating zone" used to describe indirect fire from an M-60, or machine gun. It was indirect, plunging fire used either for recon by fire, or if we had spotted some folks that were in range, but not from direct fire weapons, and we could not get a fire mission quick enough. I seem to remember he would traverse the area, and it appeared from the tracers that he got ok coverage in a small area arcing or lobbing the rounds in. The only other time I saw this used was a Quad .50 worked over a valley below a small fire base I was on. They had literally a ton of ammo in the bunkers, and it impressed me.
Noslack
In my mini-museum (china cabinet in my office) I still have an original Firing Table for the M-60 Machine Gun. Just like the firing tables for artillery, it gives range vs. elevation (in mils) for the M-60 MG.
That's why there are flats machined into the top of the M-60 barrel, they are for the gunner's quadrant.
Machinegun training tasks have changed somewhat with time as a result of differences in accepted employment techniques. In the era of World War I, for example, machinegun companies and even battalions were employed. Special training was required for officers assigned to these units because indirect fire was a common role for the employment of machine guns at that time. Training called for indirect target engagements to a distance of 2,000 yards. Tripod use on machineguns permitted effective use of the machinegun in an indirect fire role (Merkatz, 1915; Musham, 1921; Indirect Fire-Machinegun, 1923; Heavey, 1936; Hutchison, 1938; Marshall, 1951). When machinegun crews were organized into companies in wars before the Korean Conflict, the indirect fire mission for the machinegun was considered important. After the U.S. Army experience in Korea, this mission and the training with which it was associated lost its place in the POIs. The nature of the terrain in Korea and the
beginnings of fluid engagement may have caused a shift away from an emphasis on indirect fire employment for the machinegun (Marshall, 1951). Currently, this mission is no longer taught.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA169944&Location=U2&doc=GetTRDoc.pdf
I recall the term "beaten zone or beating zone" used to describe indirect fire from an M-60, or machine gun.
The beaten zone is the area of the ground upon which the cone of fire falls.
The beaten zone applys to all classes of fire with respect to the ground, but is easier to identify when it is plunging fire as opposed to grazing fire.
Indect fire is a means of employment, not a class of fire.
Some of the terms concerning employment, characteristics and classes of fire are being confused for one another in this thread.
You need to look for TR 240-15 Machine Gun Techniques of Machine Gun Fire, Indirect Laying, 1925
This is the bible of the lost art of indirect fire with machine gun. Firing overhead, firing over mask, laying in more than one gun.
It opens up more of the battle space to the SBF positions.
Post WWI was the high point of machine gunnery and it carried into WWII. It fell off after that
This is an old post, recently reactivated.
There are Firing Tables for the M-60 machine gun.
The nomenclature is "FT-7.62-A-2".
We had them 38 years ago in Korea. I guess they are still in the Army publication system.
They were thin booklets, about 8 pages, with the orange/brown cloth cover.
Inside were the elevation required to hit a target at a given range.
You will find the reference to the Firing Tables in the back of the operators manual.
(See image).
Supposedly, the tops of the gas port on the barrel were machined flat, so as to be parallel to the centerline of the bore (See picture of M-60, note arrows).
Then, by looking up the range desired in the firing table, the gunner would determine the elevation required. The necessary elevation would be dialed in the gunners quadrant (see image), the quadrant would be laid across the flats, and the gun elevated with the Traversing and Elevating mechanism on the tripod until the bubble was centered, not unlike elevation for a mortar tube.
Azimuth/deflection was a matter of compass work.
In theory, my six M-60's (I had a Recon Platoon, with six "Rat Patrol" gun jeeps, each with an M-60 with tripods) could be laid for direction in defilade, elevated, and commence fire towards a target without the gunners ever seeing their target.
We never even practiced it. Seemed like a huge waste of ammunition.
This is an old post, recently reactivated.
I've observed this in action. It was used to lay a helicopter trap and downed three Soviet helios (including one of the first 'flying tanks'). Three M1917A1s configured in .303 were situated where the helios were expected to make a gun run on a village. They flew into a steel rain squall. First two crashed landed within a klick, the third pulled up into one of the sheets of rain and dropped like a stone backwards to the ground.
Used a USAAID child's protractor, a plumb bob, and the FT.
Lots of goat for dinner that night.
Allegedly...
mojaveman
01-31-2014, 11:46
I've observed this in action. It was used to lay a helicopter trap and downed three Soviet helios (including one of the first 'flying tanks'). Three M1917A1s configured in .303 were situated where the helios were expected to make a gun run on a village. They flew into a steel rain squall. First two crashed landed within a klick, the third pulled up into one of the sheets of rain and dropped like a stone backwards to the ground.
Used a USAAID child's protractor, a plumb bob, and the FT.
Afghanistan in the '80s?
Loadsmasher
01-31-2014, 11:59
I've observed this in action. It was used to lay a helicopter trap and downed three Soviet helios (including one of the first 'flying tanks'). Three M1917A1s configured in .303 were situated where the helios were expected to make a gun run on a village. They flew into a steel rain squall. First two crashed landed within a klick, the third pulled up into one of the sheets of rain and dropped like a stone backwards to the ground.
Used a USAAID child's protractor, a plumb bob, and the FT.
Lots of goat for dinner that night.
Allegedly...
I love this forum.
The "beaten zone" as defined in WWII and possibly all other wars is: "an area of where bullets have fallen at max range (1,000 yards) into a particular pattern due to the vibration of the weapon when firing." Now would the 7.62mm mini-gun mounted on a vehicle or in a place of defense still be considered as an in-direct weapon?