SUPPRESSIVE FIRE...DOESN'T

Who is actually putting out the most suppressive fire?

The tongue-in-cheek humor of Murphy’s Laws of Combat states:“Suppressive fire…doesn’t.”

Being a battle rifle and marksmanship fanatic and also striving hard to achieve curmudgeon status, of course I agree. But I’m just an obnoxious blogger. Let’s see what some more qualified grumpy old farts had to say about the subject.

“Volume of fire can seldom replace accuracy of fire in a small war. The morale of guerrilla forces is little affected by the loss of u particular position, but it is seriously affected by the number of casualties sustained in combat.”
USMC Small Wars Manual

“You have to KILL these Jap before they will leave. Just turning a large volume of fire in his direction will not make him leave.”
U.S. Army Captain H. L. Crook, Guadalcanal

The Germans, never noted for linguistic brevity, said simply, “Shooting at random over the ground occupied by the enemy accomplishes nothing.” “Victory comes to the one who fires the largest number of well-aimed shots against his opponent in the shortest time.”
German WWII Squad Infantry Manual

“You must have forgotten what happened in the American Revolution. We won that war with accurate fire, when the enemy had all the volume. It won at Kings Mountain and Saratoga, and every other battle we won. And real shooting almost whipped the mass-firing Federal army in the Civil War. It’s still like that, anywhere I’ve seen men shooting it out. You don’t hurt ‘em if you don’t hit ‘em!”
USMC legend Lieutenant General Lewis "Chesty" Puller

“The primary job of the rifleman is not to gain fire superiority over the enemy, but to kill with accurate, aimed fire.”
Former United States Army Chief of Staff General Joseph “Lightning Joe” Collins

"It is rifle fire that ultimately takes ground, and it is rifle fire that holds it after it's taken, by throwing back enemy counter-attack. The man with the rifle is the man who wins wars; and accurate rifle fire from individual riflemen is the most effective factor on any battlefield."
USMC Raiders commander Brigadier General Merritt Edson, just after WWII, stated,

“The best plan, the best leadership, and the most skillful fieldcraft will avail nothing if the men cannot shoot to kill when they meet the CT [Communist Terrorist].”
British ATOM Manual

“If the fighting Army does nothing else, we must be able to hit our targets. Conversely, if we do all other things right, but fail to hit and kill targets, we shall lose.”
Vice Chief of Staff General John Vessey, 1980.

"Weapons handling and combat marksmanship must be stressed as well. Rapid, accurate target engagement ensures the outcome not only with adversaries, but also limits collateral damage."
Kennedy School of Advanced Warfighting 2002

“The two most important training requirements are supreme physical fitness and the ability to shoot accurately at fleeting targets at short and medium range.”
Rhodesian COIN/ATOPs Manual

Now, going beyond the quotes, for the Vietnam War, an exhaustive study was conducted on suppressive fire, a 400+ page document with the typical succinct and catchy military title of The Identification of Objective Relationships Between Small Arms Fire Characteristics and Effectiveness of Suppressing Fire. This study surveyed mostly US Army and USMC infantry combat veterans to answer, rate, or evaluate a series of scenarios and rate which weapon system would suppress them most effectively. There was also some input from ARVN forces and captured North Vietnamese POW’s. When referred to, rather than repeat that title, I will just call it “the Vietnam Study”.

Even before the Vietnam study, S.L.A. Marshall and intelligence officers from the 8th Army were doing some earlier studies on the suppressive effects of weapons during the Korean War.

Both the North Koreans and the Red Chinese used the Russian (or copies thereof) PPSh sub-machine gun, a light, simple weapon designed specifically to put out a high volume of fire. With a high cyclic rate of fire of 900 rounds per minute, GI’s called it the “burp gun”. The drum magazine held an impressive 71 rounds of ammunition. Unfortunately for the Reds, that ammunition was pistol ammunition, and rather weak pistol ammunition at that; the 7.62x25 Tokarev. Although feared by UN forces in close-range engagements, especially at night, when it was used to provide suppressive fire at any range it was ineffective and when used for marching fire it was all but ignored.

7.62x25mm Tokarev, 85-grain bullet at 1,500 fps; not suppressed.

On the American side was the new-fangled M2 carbine, with a full automatic selector switch and a 30-round “banana clip”. It had a cyclic rate of fire of 750 rounds per minute. It too, however, was chambered for the .30 USC carbine round which, although not technically a pistol caliber, was in the same category and performance as a .357 Magnum pistol round. Studies and interviews conducted on POW’s during the war strongly indicated that the M2 on full auto had very little suppressive effect on the North Koreans and Chinese.

Caliber .30 USC, 110 grain bullet at 1990 fps...not suppressed.

Nobody, but nobody, could ignore the U.S. .50- and Red .51-caliber (12.7mm) heavy machine guns; these big guns suppressed the ever living hell out of anything in their path. Yes, despite what she told you, size DOES matter.

Caliber .50 BMG, 709 grain bullet at 3,000 fps.

SUPPRESSED!!!

The Vietnam study also noted that in both offense and defensive actions, everyone agreed by a large margin that the #1 most dangerous weapon to face was the .50-caliber or 12.7mm heavy machine gun. Ranked in order after that came the .30-caliber machine guns, both friendly and enemy, with the assault rifles coming in last amongst the small arms. Also noted, grenade launcher HE grenades rated highly near the .50-caliber HMG but standard hand grenades ranked very low.

It appears that the Taliban would also agree.

"Many of the proponents of 5.56 mm ammunition argue that it is better at suppressing an enemy than 7.62 mm ammunition due to the higher volume of fire it permits. However, recent research conducted by the MoD2 shows that a near miss from a large calibre 7.62 mm or 12.7 mm round has a much greater suppressive effect than 5.56 mm round. Larger calibre bullets, with increased noise and visible effect, also suppress when they miss by a greater distance than 5.56 mm ammunition. These findings are supported by anecdotal feedback: ‘The Taliban ignore 5.56 mm, are worried by 7.62 mm and fear 12.7 mm rounds.’"
From a British MOD study

"An interesting point: the BA noted that the Taliban were very good at concealment and most troops never saw them during fire-fights. The best they could usually do was to locate the general direction of incoming fire and use their small arms to suppress the enemy and fix them in place until artillery or air support could be called in. Much work had been done on analysing suppression, and it had been calculated from field trials that 40mm HV AGL fire could suppress people at miss distances of 59 metres, .50 BMG at 24m, 7.62mm at 6m and 5.56mm at 3m (in the case of the rifle/MG rounds, it was the volume of the supersonic 'crack' which made the difference, and that's directly linked to bullet energy)."
Tony Williams, British Small Arms Expert

"The problem is suppressive fire does not do well with a light, barely lethal bullet at the distances of engagements in Afghanistan."
American military comment on the 5.56mm round.

Suppressive fire by itself, if it does not cause casualties, quickly loses its effectiveness.

A fairly recent article in Infantry Magazine by Captain Daniel Morgan, an infantry veteran of Operation Iraqi Freedom, makes that same old point all over again: “Marksmanship is the core of excellence for an infantry Soldier. Their proficiency in killing wins the battle. The more you suppress a target without killing or wounding the enemy, the bolder he becomes in attacking you. You need to train your Soldiers to aim, fire, and kill.”

The Vietnam study noted the same thing: “…unless the weapon is truly effective as a casualty producer under combat conditions, experience with it (i.e., exposure to it) will diminish initial fear."

A two-tour Vietnam Marine Corps infantry officer once told Jeff Cooper, “…if the gooks were on full auto [AK-47’s] he could approach with comparative safety to within fifty meters. If they were on semi, he might expect to take casualties at 150, or even beyond.”

The Vietnam studies also showed that accuracy of fire was always a very close second to volume of fire in effectiveness

Most Suppressive
Characteristics of Enemy Fire

High rate 48%
Accuracy 44%
Caliber 4%
Loudness 4%

Even though I am a big-bore rifle and accuracy fanatic, I couldn't believe how effective a single, accurate sniper could be in suppressing enemy troops. Suppressive fire can be light but accurate, and it turns out to be just as effective, if not more so, than pure heavy volume fire.

From the study, it would seem that many Vietnam veterans would agree with Captain John Thomason, who fought with the Marines in WWI when they introduced the Germans to what real rifle marksmanship was all about:

“The Boche wanted Hill 142; he came, and the rifles broke him, and he came again. All his batteries were in action, and always his machine guns scourged the place, but he could not make head against the rifles. Guns he could understand; ht knew all about bombs and auto-rifles and machine-guns and trench-mortars, but aimed, sustained rifle-fire that comes from nowhere in particular and picks off men—it brought the war home to the individual and demoralized him.”

From the Vietnam study:
“According to one ‘Lessons Learned’ report from Vietnam, sniper fire, which is typically low-volume, high-accuracy rifle fire, has been recognized as being highly suppressive in all wars, and the Vietnam experience is no different.

Assume that you are on an offensive mission sweeping through a series of rice paddies. Which of the following would most likely cause you to hit the ground or take cover?

[In order, percentages not given]

(1) Sniper fire from a hidden position
(2) Automatic rifle fire from a woodline
(3) An RPG impacting near you
(4) Grazing fire from an enemy heavy machine gun.

“Assume that you are in your foxhole in a defensive perimeter. Which one of the following circumstances would be the most effective in pinning you down? (check only one)”

(1)A sniper fires at you along with automatic rifle, machine gun, and RPG fire. 65%
(2) A single sniper fires at you from an unknown position. 24%
(3)A sniper fires at you along with automatic rifle and machine gun fire. 9%
(4) A sniper fires at you along with an automatic rifle. 1%
(5) A sniper fires at you from a nearby clump of trees. 1%

“Assume that you are on an offensive mission with the objective of taking a village. Enemy small arms have just caused you to take cover. Which of the following is most likely to keep you down and prevent our further movement in the assault?”

[In order, percentages not given]

(1) Accurate sniper fire from a hidden position.
(2) Heavy volume of automatic rifle fire.
(3) Heavy volume of RPG rounds coming into the area of your position.
(4) Grazing fire from an enemy .30-caliber machine gun.

"It is interesting to note that a number of individuals felt that they would be more suppressed by seeing individuals around them wounded without hearing the rounds or the weapon than by increases in weapon and projectile signatures."

Another thing that really surprised me was some of the ranges involved. It’s a universal (mis)conception that all of Vietnam was dense jungle and firefights all took place at spitting distance. This study showed that while fully half of the firefights took place at less than 160 meters, 10% occurred between 300 and 400 meters, and 14 percent over 400 meters. I found that quite interesting; 24% of the shooting, almost a quarter, occurred beyond the assault rifles’ generally accepted effective range. Yet the military establishment and McNamara’s Wonder Kids had made up their minds, and the no-need to-engage-beyond-300-meters mentality…and weapons…remained.

"When you’re under hostile fire which of the following thing bugs you the most?"

(1) The sound of passing bullets 34%
(2) The sound of their weapons firing 16%
(3) Seeing bullets hit trees, dirt, etc. 10%
(4) Seeing tracers coming at us 8%
(5)Seeing their muzzle blasts 3%
(6) [Other dealt with grenades]

In response to taking fire, almost to a man everyone quite sensibly indicated that they hit the dirt. The next response, for fully one third of the men, was to fire toward the sound of enemy weapons. There's not much else one can do without an identifiable target. Eleven percent tried to find a specific target to fire at. Only 6% found, identified, and accurately engaged a specific target, usually enemy muzzle blasts or smoke.

How effective this form of fire was is debatable. “Troops must therefore be practiced in firing from the shoulder in the standing, sitting and kneeling positions. On fleeting encounters, experience has shown that aimed fire from the shoulder, in the standing position is the most effective. In very close country, experience has shown that to be effective, fire should always be directed at a SEEN target. Firing at noise or sign of movement is seldom effective…”
British ATOM Manual, original emphasis.

There's just too much to the study to go into more detail. Lest I be called a complete nay-sayer, it seems that suppressive fire actually is quite effective, when done by a real honest-to-God machine gun (not a full-auto assault rifle) or grenade launchers. Once fire superiority is gained, those weapons can effectively and economically keep the enemy pinned for friendly maneuver to take place. Apparently, just four 6-10 round MG bursts per minute, dispersed into the enemy positions, keeps their heads down quite effectively.

Here's a quick run down of the conclusions at the end of the study.

Based on the analysis of the literature and the data collection efforts in this study, the following general conclusions have been derived:

(1) The primary determinants of suppression in order of apparent importance are:
a. Volume of incoming fire
b. Proximity of incoming rounds to the individual
c. Type of weapon employed against the individual.

(2) Signature effects relevant to suppression are:
a. Loudness of projectile signature is equated with suppression.
b. Unique projectile or weapon signatures may create suppression.
c. Visual and auditory signatures associated with impacting rounds affect suppression.

(3) Factors which tend to mediate the suppressive effects of weapons are:
a. Nature of the mission.
b. Availability of cover.
c. Combat experience of the individual
d. Training
e. Time in combat
f. Psychological makeup of the individual