24 February 2016


Limited Range Bullets To Reduce Collateral Damage

The Problem

A .50 caliber (12.7mm) bullet, commonly used in heavy machine guns and sniper rifles, travels more than two miles after it is fired if it doesn't hit something else first.

In a sniper rifle, designed to accurately hit targets following careful and thoughtful aiming at long range, this is a feature.

In a machine gun, which is usually fired at ranges of less than a mile, often in bursts of fire and rarely with much introspection, this is a bug because bullets that don't hit their intended target (which is a lot of them) hit an unintended target and often cause undesirable collateral damages to people or property.

Similarly, handguns are generally used against adversaries at 30 to 50 yards.  Even an expert aiming carefully would consider hitting a small target at a range of 100 to 200 yards (one or two full football fields) with a handgun to be an accomplishment.  But, a handgun round typically travels from 200 to 900 yards if it doesn't hit something else first.

A stray bullet can go through motor vehicles or walls before stopping, although this impact reduces the distance that it will travel depending on the mechanical properties of whatever is hit.

The long range that a bullet travels is even a problem for target shooters, because people at firing ranges practice at the long end of the range where their weapons are accurate in the heat of a firefight, but if a bullet misses the target it could go far beyond the target range, requiring shooting ranges to hold open a lot of empty space past the shooting range for safety's sake or to build an imposing bullet proof wall that could cause a stray bullet to ricochet back at someone shooting at the range.

So, with the pretty much singular exception of a sniper rifle, the fact that bullets travel much further than the intended target is a flaw for most people using a firearm for its primary purpose of injuring or killing other people or animals.

The Solution

But, the most obvious way to reduce the range of a bullet, by slowing the speed at which it leaves the firearm, is also not desirable.  A slower bullet is less accurate at any given range (in the hands of an ordinary firearm user) and delivers less kinetic energy so it is less likely to stop the person or animal that the person using it is trying to hit.

Employees at the U.S. Army Armament Research, Development and Engineering Center, however, have identified this problem and patented a bullet design that could solve it (which they call "Limited Range Projectiles"). Basically, a fuse in the bullet that is triggered when the bullet is fired causes the bullet to self-destruct comparatively harmlessly before it hits anything else, once it reaches its designated range, unless it hits something else first.

For example, a police department could issue its officers bullets for their sidearms that self-destruct after 100 yards, thus reducing the likelihood that stray police bullets cause collateral damage, without impairing the effectiveness of the bullet against its intended target at anything less than 100 yards away from the officer firing it.

Engineers are also working on "smart bullets" that can be individually programed to explode at a given distance or to track of target during its flight.  But, limited range bullets require no such deliberation and are suitable to use as a standard round for most firearms in most applications, because the longer ranges travelled by ordinary bullets are almost always a flaw in firearms used in ordinary ways.  One can even imagine gun control lobbies at least favoring legislation to encourage or subsidize such rounds to reduce the risk of accidental injury to members of the public.

How Are Sniper Rifles Used In Modern Warfare?

Of course, there are circumstances when it makes sense, particularly in the military and for SWAT teams, to use sniper rifles to fire at people at long range.  Usually, these rifles use rounds between 7.62mm and 12.7mm, with an 8.6mm (.338 caliber) Lapua Magnum round, which was introduced in the 1990s and has been favored by professionals making that decision afresh since about 2003.

The 8.62mm round has an effective range of about 1,500 meters, compared to about 1,000 meters for a typical 7.62mm sniper round, while the rifle, the ammunition and its gear weigh only slightly more than a conventional 7.62mm sniper rifle.  The 12.7mm round has an effective range of about 2,000 meters but has combined weight of the 12.7mm rounds and associated rifle and gear is twice as heavy at the 8.62mm round and its rifle and kit used to fire them, which can be cumbersome for the sniper. Of course, the ranges are relative and depend to some extent on the skill of the sniper using them.

While I am no hawk on defense and I am usually loathe to applaud any kind of killing, there are some uses of this technique that are undeniably righteous.  Consider the following example:
In this case it was a situation in Syria where a British SAS commando used an Israeli 8.6mm sniper rifle to kill an ISIL (Islamic State in Iraq and the Levant) instructor. The ISIL teacher was about to show his students how to behead prisoners by using a live victim. The British sniper was 1,200 meters away and managed to hit the ISIL instructor in the head at that range. The head shot caused the skull to sort of explode, which apparently made an impression on the ISIL recruits because the SAS sniper was using a new Israeli designed rifle equipped with a suppressor. This is not a silencer but it does greatly reduce the flash and sound of the rifle. For long range shots this means those on the receiving end have a very difficult time telling where the shooter is and that often causes panic.
A few other examples from the same source illustrate how military forces have used sniper rifles at the limits of their range in recent years:
Between 2009 and 2015 the distance record for sniper kills was held by a .338 rifle. In 2015 that record was broken by two Australian snipers in Afghanistan using M82A1 12.7mm (.50 caliber) rifles. In a coordinated shot at a Taliban leader 2,800 meters away the two snipers fired simultaneously and six seconds later the Taliban chieftain fell dead. It will never be known which of the two shots got him. The victim would not have heard the shot, the rifles were so far away and the bullet was travelling faster than the speed of sound. About two seconds later anyone with the dead Taliban man would have heard the two shots, but faintly as the shooters were nearly three kilometers (two miles) away. 
The previous record shot was made in November 2009 by a British sniper (corporal Craig Harrison) who killed two Taliban in Afghanistan, at a range of 2,620 meters (8,596 feet). He did this with a L115A3 rifle firing the 8.6mm Lapua Magnum round. Before that the record was held by a Canadian soldier, corporal Rob Furlong, who dropped an al Qaeda gunman at 2,573 meters (7,972 feet) in 2002, also in Afghanistan with a 12.7mm rifle.
As a point of reference for residents of my native Denver, these distances are roughly the entire length of the 16th Street Mall which goes all of the way from one end of downtown to the other. As a purely technical accomplishment, this is stunning.  And, sometimes, even often in our own military and the militaries of our allies, this technology is used appropriately.

Sometimes life in the military really is every bit as dramatic as the movies.

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