What are the Fastest Firing Guns?

Ever since the invention of the first man-portable firearms, people have been interested in shooting them faster. A good revolutionary war era soldier could get off three shots a minute from his smoothbore musket, and breech-loading designs sped that rate of fire up considerably.

By World War I, a well-practiced British infantryman could accurately fire 30 or more shots into a target at 300 yards using his Short-Magazine Lee Enfield bolt-action rifle in one minute. All major armies of the time were utilizing mounted air or liquid-cooled machine guns firing at up to 600 rounds per minute, which proved devastating in the era's trench warfare.

Image: Vickers Water Cooled .303 British Machine Gun

However, time and technology move on, and today there are firearms and weapons systems capable of astonishing fire rates. In this article, we will look at some of the fastest-firing guns ever made.

Calculating a firearm’s rate of fire mathematically

The first and most basic method for determining a firearm’s fire rate is observation, a stopwatch, and simple math. Suppose you load a 100-round ammunition belt into your machine gun and start the stopwatch when you pull the trigger. In that case, you can easily calculate approximately how long it takes to expend that entire belt of ammunition. If it takes 12 seconds, for example, you take 100 rounds / 12 seconds X 60 seconds in a minute = 500 rounds per minute rate of fire. If it takes you 1.5 seconds to empty the 32-round magazine of your M-11/9 submachine gun with a suppressor fitted, then 32 / 1.5 X 60 = 1,280 rpm rate of fire.

Video: Video Cobray M11/9 Mac 11 Submachine Gun

This also works for determining the average rate of fire for semi-automatic firearms. If it takes a shooter 5.5 seconds to shoot 30 rounds out of a standard AR-15 magazine, then using the formula above, we know it averages out to around 327 rounds per minute average rate of fire, even if the shooter starts firing faster and then slows down near the end when his or her finger gets tired, you can still find the average ROF.

Of course, the shorter the time, the more room for operator error due to starting and stopping the stopwatch exactly on time. So there are other, more accurate methods for determining a firearm’s true rate of fire.

Video: Measuring Rate of Fire

Using an optical/mechanical sensor or shooting chronograph

Some large military auto-cannons and machine guns utilize either a mechanical counter or an optical sensor to verify or determine the proper rate of fire, generally by either the speed of rotating barrels or by counting the shell casings of a belt of ammunition as they pass by a sensor. This is obviously impractical for most civilians, so some people use a shooting chronograph to determine their guns' fire rate.

A chronograph is intended primarily to accurately measure the speed of a projectile, but some chronographs are also capable of measuring the rate of fire of fast-firing guns by calculating the time between projectiles passing over the chronograph’s optical sensor.

A traditional optical/shadow-based chronograph can often have trouble with this. However, magnetic, barrel-mounted chronographs and the new doppler radar chronographs are capable of providing accurate rate of fire information under the right conditions.

Many acoustic shot timers will calculate the rate of fire

By far, the most popular and widely used method for calculating the rate of fire, particularly for civilian or sporting use, is using a firearm shot timer. These devices can detect the sound of each shot. They provide accurate information about each string of fire, including the overall time from the first shot to the last and the split times between each shot, and most can process the information accurately enough to provide an overall rate of fire, even for machine guns in many cases.

This method can be problematic if the timer's settings are not optimized for the environment. For example, shooting inside an echo-prone shooting range can often overwhelm the microphone and processors of a shot timer, and it may report 5 shots as one shot, if they are fired in a short-enough period of time. Additionally, a rotary-barreled cannon that fires several thousand rounds per minute may sound like a single BRRRRRRRRRRP to many acoustic shot timers, and you may not get accurate readings, depending on the timer’s settings.

Image: G18 – Fully automatic 9mm

The difference between a machine pistol and a submachine gun is that a machine pistol looks and feels like a regular handgun, and may function as one. In contrast, the submachine gun is essentially a small carbine designed to be fired from the hip or shoulder using two hands in different positions on the gun.

The Glock 18 is a full-auto variant of the popular Glock 17 and can fire up to 1,200 rounds per minute. Holding onto one of these bullet hoses without a shoulder stock to help you tame the recoil is a handful, to say the least, but well-trained shooters can place a surprisingly high number of shots on a target from reasonably close ranges. The Glock 18 is one of the rarest Glock pistols worldwide, despite being featured in hundreds of movies, TV shows, and video games.

Video: The Full Auto Glock 18C Machine Pistol

Image: KRISS Vector SMG

The Vector is so named because its operating mechanism transfers much of the force of the action downwards at an angle, rather than straight back into the shooter’s shoulder, which makes this funky-looking subgun one of the most controllable fast-shooting guns ever made.

Video: Kriss Vector empties a full magazine in under a second

In the more traditional fully automatic mode, the AN-94 fires at a much more manageable 600 rounds per minute, like a typical AK-47. But in its 2-round burst setting, those two rounds are fired so quickly that it sounds like a single shot.

Video: Shooting Russian AN-94

Image: MG42 Belt-fed Machine Gun courtesy of NRA Shooting

At such a high fire rate using full-powered 8mm Mauser rifle cartridges, it chewed through ammunition (and barrels) quickly, which is one reason most modern infantry weapons intended for a light-machine-gun role have since typically limited their rates of fire to around 800 RPM or lower. But it can’t be denied that the MG42 was devastatingly effective and sounded terrifying.

Video: Shooting the MG-34 and MG-42

For this reason, John Browning’s M2 and M3 machine guns were developed in aircraft variants capable of firing up to 1,200 rounds per minute (in the AN/M3 model). Well, the Rikhter R-23 puts all other single-barreled machine guns to shame. The R-23 autocannon was developed starting in the late 1950s for the Soviet air force for use as a defensive weapon on large bombers.

The cannon uses a distinctive 4-chamber revolver-type design rather than the typical belt-feeding mechanism, and it takes advantage of the expanding gas from its fired 23x260mm telescoping cartridges (where the tip of the projectile is close to flush with the mouth of the case) to cycle the action, load a fresh round, and expel the spent shell casing. Capable of firing up to 2,600 RPM, the R-23 was the fastest-firing single-barrel autocannon ever put into service, and, interestingly, was actually fired experimentally on the USSR’s Salyut 3 space station.

Video: The Soviet Rikhter R-23 Space Cannon

By distributing the work needed for cycling the action among two barrels, the rate of fire is greatly increased, up to 3,400 RPM. Additionally, with two barrels and mechanisms, the mechanical wear is also spread out, so barrels need replacing only half as often.

Although it can’t achieve the sustained rate of fire of an externally powered rotary-barreled cannon such as the M61 Vulcan (see below), the GSh-23’s initial time to first projectile impact can be quicker than that of a rotary cannon due to the double-barreled design’s not needing to spin up to fire.

Video: Shooting 2 x GSh-23 twin barrel 23 mm autocanon from tail turret in Il-76

The M61 Vulcan cannon is widely used in the USA’s fighter and strike aircraft, with variants powered by electric motors, pneumatic systems, or hydraulics. These separate drive systems are necessary due to the incredible firing rate of the cannons, which requires separate mechanisms for feeding the ammunition belt, rotating the barrel assembly, and chambering/firing/extracting shell casings. By separating all of these functions and spreading out the firing cycle across 6 barrels, the M61 cannon can achieve truly face-melting rates of fire, typically 6,000 rounds per minute but up to 6,600 RPM in the lightweight M61A2 variant.

Due to the weight of the ammunition, most aircraft can’t carry anywhere close to a full minute’s worth of ammo (since at 6,000 rounds per minute, that means the M61 fires 100 rounds every second). Most aircraft utilizing the M61 carry between 600 and 1,000 rounds of ammunition maximum. In fighter aircraft, the firing bursts are typically limited to between 3 and 50 rounds per trigger pull (50 rounds being half a second of firing).

Video: The M61 Vulcan is a Gatling Gun on Steroids

Of course, since it’s electronically controlled, you can fire as fast as you want, as shown in the demonstration video below. During the demonstration, the prototype Metal Storm multi-barreled array fired volleys at 600, 30,000, and 60,000 RPM before a final 180-round burst of just over 1 million rounds per minute in 0.01 seconds (approximately 27,778 RPM per barrel X 36 barrels).

Video: Metal Storm 36 Barrel Prototype-One Million Rounds per Minute Rate of Fire

Though the system has appeared in several video games over the past decade or so, it still hasn’t made it to military production or adoption, perhaps because its utility is limited and its loading and firing procedure is so tedious (and the automated position-defense role has so far been effectively covered by the CIWS Phalanx). But regarding the maximum rate of fire, the Metal Storm is the undisputed king.