The Real Role of Small Arms in Combat

Monday, February 27th, 2012

The real role of small arms in combat, Dr. Jim Storr reminds us, is not to kill the enemy so much as to do something else:

Since the Boer War, if not before, infantrymen have been unable to advance in the open against tolerably well-organised defences equipped with rifles. The attackers’ casualties are simply too great. The minimum requirement for a successful defence is quite modest: high-velocity, conoidal bullets fired from half-decent breech-loading rifles. Anything more, such as automatic weapons, simply makes the attackers’ job even harder. In the early part of the 20th Century different armies came up with different ways of overcoming that problem. Many involved artillery or tanks. Some involved infantry heavy weapons, such as mortars. Most included a form of organisation and tactics by which the attacker used small arms fire to suppress the enemy. That enabled the attackers to move forward to the point where they could use bayonets, grenades and very-short-range small arms fire (at ranges of perhaps a few feet) to incapacitate any defenders who continued to resist. Critically, however, there was never much rational, explicit analysis as to how that took place.

A few studies are quite insightful. It appears that a soldier’s ability to hit a given target is typically reduced by a factor of ten or so when he is moved from a static rifle range to a field firing area where he has to select cover, move, shoot and so on. It is reduced by a further factor of ten or so if there is an enemy firing back at him. It is reduced by another factor of ten if the enemy has machine guns, or if he has tanks; and by a hundred if he has both. We begin to see why many thousands of rounds can be fired, but very few actually hit.

Another study reveals entirely different phenomena. It highlights that achieving surprise, or inflicting shock on the enemy are hugely effective. These are more effective than any likely force ratio, or the use of other weapon systems, and so on. Put very simply, if the attacker can find the enemy’s flanks and rear and attack him from there, or apply sudden concentrated violence to him and then exploit it, the enemy will typically give up quite quickly. He will then either withdraw, if he can, or surrender. A number of issues interact here. One is that using covert routes to find the enemy’s flanks and rear is clearly a good thing. Another is that the use of tanks or indirect fire to stun the enemy is very helpful. But within all of those tactics there is another critical factor: the attacking infantry’s ability to suppress the defender. That enables the attacker to move forward: either to close quarters to use bayonets and grenades, or around and past the defender’s positions to attack him from unexpected directions.

Although relatively few of the enemy are typically incapacitated by small arms fire, their location and identity is often critical. For example, the clearance of one trench may allow the attacker to get behind several more, and start to roll up the position.

Suppression is the effect of small arms and other weapons systems which temporarily prevent the enemy firing its weapons or moving in the open. In simple terms, it makes them keep their heads down. It is critically important. In the offence it allows the attacker to move forward, to find gaps and weak points, and exploit them. In the defence it prevents the enemy moving forward and firing, and thereby sets him up for counterattacks. In both cases it pins the enemy down for incapacitation (or destruction) by other weapons.

For the last century or so, Dr.Storr reminds us, most rifles have been more accurate than their riflemen:

A typical rifle — be it bolt-action or semi-automatic — will form a group of perhaps 40mm or better at 100m, if fired from a vice or clamp. A reasonably well-trained soldier firing the same weapon on a range can group at perhaps 100mm at the same distance. Very few armies train their soldiers to consistently beat that sort of accuracy. This has a huge consequence, which very few armies acknowledge: the weapon is in many ways irrelevant. As most modern small arms are more accurate than their firer, it makes very little difference which weapon is selected. There are many other parameters. Reliability, weight and ergonomics are all important. But accuracy is almost irrelevant, because many weapons are ‘good enough’ in that regard.

What is far more important is to train the soldier to get the required effect from his small arms. In most armies he is trained to hit targets out to 300m or perhaps 600m. Yet in battle he rarely does that. He is rarely, if ever, trained to do what he really needs to do: suppress the enemy. Field research carried out in the Second World War provided a useful metric for small arms suppression, as did some more recent analysis. We can consider three cases: the need to suppress an enemy; the need to keep him suppressed; and the need to re-establish suppression once lost. In general, small arms fire has to pass within roughly a metre from the outline of the target to be effective. A small number of rounds passing through that area in a few seconds (perhaps 3 to 5 rounds in as many seconds) will suppress the target, or re-suppress him if required; whilst just one round every three seconds will keep him suppressed. That seems quite achievable.

With a little coaching and feedback, a section of riflemen was able to suppress a (simulated) target more than twenty times as long with the same amount of ammunition.

Now, if riflemen can hit within a meter of their target, but not within centimeters, perhaps they should be shooting shells with a one-meter kill radius.


  1. Madera Verde says:

    Why is he assuming that 3 rounds per 5 seconds within a meter of the target is “suppression”? Unless there is a reason behind that it seems that he concluded that if you program a target to behave a certain way, you can change your own behavior to game that target.

    Is your last paragraph a reference to the XM25? Are you saying the basic role of infantry is changing and that weapons like the XM-25 is restoring the balance infantry defense and offensive power?

  2. Isegoria says:

    I had the same question about where his definition (of what qualifies as successful suppression fire) came from, but I think it’s a reasonable estimate, even if it doesn’t turn out to have rock-solid evidence behind it. The key concept remains: small arms suppress far more often than they neutralize, so we should modify our tactics to “game” enemy-combatant psychology.

    Yes, my last paragraph was referring to smaller-caliber grenade-launchers, like the XM25 — and the Russians’ simpler 30-mm AGS-17 and AGS-30 launchers. Any grenade-launcher design trades off payload (and thus blast radius) against velocity (and thus distance and accuracy), and most current designs lean toward a relatively big 40-mm grenade lobbed at relatively low velocity, like a very light mortar. Another alternative would be to shoot a small 20-mm grenade at relatively high velocity, more like a light cannon. If our troops can consistently put rifle rounds within a meter of their target, then a single round with a one-meter kill radius might be worth dozens, hundreds, or even thousands of rifle rounds. It might obviate the need to suppress and then maneuver in order to neutralize.

  3. Madera Verde says:

    Yes, I suppose it would be difficult to get good data on what exactly suppresses, considering it is mostly psychological.

    So a 20-mm higher-velocity grenade-launcher would be accurate to 800 m? One of the drawbacks of a grenade-launcher is you can’t use it at close quarters. In this system you’re envisioning what do soldiers use for that, an under-barrel sub-machine-gun?

    Or if the grenade is DIME perhaps a bayonet would suffice, lol.

  4. Sconzey says:

    Maybe a shotgun might be better. Now that would be one hell of an infantry weapon: 20-mm semi-auto grenade-launcher for range. Automatic shotgun for close-quarters.

  5. Isegoria says:

    The classic M79 grenade-launcher launches its 40 × 46 mm grenade at just 76 m/s — faster than anyone can throw a baseball, but nowhere near bullet velocity — and its effective range is listed as 350 m.

    The XM25 launches its 25 × 40 mm grenade at 210 m/s — about half a pistol round’s velocity — and its effective range is listed as 500 m for point targets, 700 m for area targets.

    The XM109 “payload rifle” — a modified .50-caliber sniper rifle — launches its 25 × 59 mm shell at 425 m/s, and its effective range is listed as 2,000 m, presumably against vehicle-sized targets. Its box magazine holds five rounds — rather than 10 rounds of .50 — that sound quite effective:

    The centerpiece of the XM-109 system is the 25mm HEDP ammunition it fires. A scaled down derivative of the low velocity 30mm HEDP M789 ammunition fired by the AH-64 Apache attack helicopter, the MX-109′s 25mm ammunition has been judged to be 2.5 times more effective at destroying targets than a .50 caliber armor-piercing round. It is expected that this ammunition can penetrate nearly 40mm (an inch and a half) of armor plating at 500 meters, or blast open doors from around the corner. In other words, it gives the Soldier breaching capability on fortified positions, while minimizing exposure to enemy fire, thanks to its effectiveness at greater distances.

    So I can definitely imagine a smaller, lighter “payload rifle” with an effective range of 800 m against point targets, able to blast through most cover, yet safe to use at (fairly) close range.

    Traditional grenade-launchers are much more like light mortars — low rate of fire (compared to an assault rifle), low-velocity round with a loopy trajectory, big blast radius (compared to a bullet), etc. — while “payload rifles” are more like ordinary rifles with fewer, heavier rounds.

  6. Isegoria says:

    Shotguns are excellent short-range weapons with high hit probabilities. Traditional grenade-launchers owed a lot to shotgun design, so it was only natural to load them up with enormous buckshot rounds for close combat.

    A 12-gauge shotgun, by the way, is 18.5 mm or .73 caliber, and so-called Frag-12 explosive ammo already exists — as this video demonstrates.

  7. Sconzey says:

    Indeed, it was your post on shotguns that made me think of them just then.

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