Filling the gap

Matthew Kirkpatrick
October 27, 2011
By Matthew Kirkpatrick
In recent years numerous Canadian police agencies have bought significant numbers of police carbines. Many more have ongoing or planned patrol carbine programs, needed to counter an increased threat to police and to quickly respond to terrorist and active shooter situations. Unfortunately the debate about how to best equip officers is all too often characterized by emotional arguments, outdated perceptions and, occasionally, myths. Many observers tend to frame the discussion by insisting one weapon is better than another, and this too is a mistake. With a little investigation it becomes evident that pistols, shotguns and carbines have complimentary characteristics. Police services often overlook the very good technical information available to them. 

In recent years numerous Canadian police agencies have bought significant numbers of police carbines. Many more have ongoing or planned patrol carbine programs, needed to counter an increased threat to police and to quickly respond to terrorist and active shooter situations.

Unfortunately the debate about how to best equip officers is all too often characterized by emotional arguments, outdated perceptions and, occasionally, myths. Many observers tend to frame the discussion by insisting one weapon is better than another, and this too is a mistake. With a little investigation it becomes evident that pistols, shotguns and carbines have complimentary characteristics. Police services often overlook the very good technical information available to them.

For this discussion "carbine" will refer to a semiautomatic, magazine fed, centre-fire rifle with a barrel shorter than 20 inches. Police carbines are almost universally chambered for the .223 Remington cartridge. Other calibres are available but rarely employed and ammunition is harder to find.

Basic characteristics

Modern police carbines are invariably based on military designs that have evolved since the Second World War, based on soldier's requirements (remarkably similar to the needs of police officers), ranging from human factors to logistics and durability, including:

• detachable high capacity magazines of 20 or 30 rounds;

• semi-automatic operation;

• superior accuracy;

• ability to mount enhanced optical sights, including night vision, and accessories such as lights;

• ease of operation and maintenance;

• operable by left and right handed officers of all sizes;

• compact and lightweight;

• minimal recoil;

• excellent reliability;

• effective at ranges well beyond 100 meters; and

• functional in adverse conditions (including extreme cold, heat, dust, immersion and CBRN environments).

Ballistics

Police carbine opponents nearly always cite the "over penetration" of ammunition, referring to them as "high powered rifles." This is a facile argument on several levels. The truth is that there is no better cartridge to produce the desired effect of human incapacitation.

In a test published in comparing pistol calibre carbines, shotguns and .223 carbines, Dr. Gary Roberts concluded: "The routine issuing of 5.56 mm/.223 semiautomatic carbines for general purpose use would significantly enhance officer safety, increase police effectiveness and decrease the dangers to innocent bystanders in many situations requiring the use of firearms".

The FBI recommends that a police bullet should penetrate between 12 and 18 inches into 10 per cent calibrated ballistic gelatin to reach vital organs from any angle, including through common intermediate barriers. The correlation between this recommendation and the effectiveness of ammunition selected using this criteria in real world police shootings is well documented in published studies. FBI testing of 12 gauge slugs, 10 mm, .40 S&W, 9 mm and .233 Remington show that, of all these cartridges, . 223 is the most consistent and most closely meets the requirement.

Intermediate barriers and armour

Another objection is that the police carbine will penetrate officers ballistic vests. While this is true, body armour use is not limited to police and it is now necessary to have a firearm capable of penetrating it. To counter the threat of criminals with centre fire rifles, ceramic level IV plates are commonly issued alongside patrol carbines, further negating the argument that police should not carry a firearm capable of penetrating body armour.

Effective penetration of other intermediate barriers such as automobile glass is also desirable. Penetration into 10 per cent calibrated ballistic gelatin after passing through standard automotive glass by .223 Remington is nearly identical to .40 S&W. In the same test both 12 gauge slugs and 9 mm prove to be ineffective.

It also proves effective after being shot through sheetrock and plywood yet does not penetrate as much as any other calibre tested. The ballistic testing data, while restricted to law enforcement, is available from the FBI and widely distributed in Canadian police agencies.

The construction and length to diameter ratio of a .223 bullet also means that it is more likely to disintegrate than ricochet after striking concrete or brick. These relatively light and long bullets are easily upset and lose energy very rapidly when deflected.

Noise

Objections surrounding the sound level of police carbines are often presented, without any support. Sound level is complicated to test, however the results of a simple sound pressure level test completed for a civilian gun range is enlightening:

• 18 inch barrel, 12 gauge shotgun: 161.5 decibels

• Pistol, 9 mm: 159.8 decibels

• 18 inch barrel. .223 carbine: 155.5 decibels

Firepower

Firepower is the capacity to deliver effective fire on a target, determined in this case by two factors:

• accuracy, since critical structures in a human are relatively small, with only about 17 per cent of the frontal area producing effective hits; and

• ability of that fire to destroy those critical structures, measured by the size and depth of the tissue destroyed.

Capacity can be measured by the number of rounds available for immediate use, speed of reloading and the number of weapons realistically available.

There is no question Canadian police need more firepower to effectively counter an increased armed threat. There is also a need to mitigate the risks of deploying that firepower amongst a population that is becoming more concentrated in urban areas. A police carbine's greater accuracy and damage potential means less rounds fired to achieve the required effect. This is more consistent with the concept of minimal force than many other available firearms.

A police carbine is light, accurate, reliable and can be fitted with enhanced optical sights, lights for low light operation and high capacity detachable magazines. Carbines can be procured for costs that allow them to be placed in every police vehicle and officers can be trained in a relatively short time. The ammunition is widely available and proven safe and effective.

Shotguns have advantages of payload type ammunition ranging from breaching rounds to less lethal. Pistols have the advantage of portability. Where the range and accuracy of these firearms are limited, the carbine fills the gaps.

The demonstrated characteristics of the police carbine continues to match the needs of Canadian police services and their numbers can be expected to increase.

Can .223 Remington Cartridges be used in a 5.56 mm firearm?

Yes but...

The .223 Rem cartridge is subject to a voluntary standard laid out by the Sporting Arms and Ammunition Manufacturers Institute. The 5.56 mm ammunition is actually 5.56 x 45 mm NATO and must be manufactured to strict NATO standardized agreement (STANAG) 4172, which also specifies more stringent testing and tighter controls of dimensions. The 5.56 mm cartridge is a derivative of the .233 Rem but differs in a few key areas.

The chamber, specifically the lead area (distance from the front of the chamber to the start of the rifling), is larger in 5.56 mm firearms. The lead in .223 Rem is 0.045 inches; the 5.56 mm is 0.164 inches. This means that, while the case is identical, the overall length of 5.56 mm cartridges may be longer and may not fit into a .223 Rem chamber without crushing the bullet into the case.

The 5.56 mm ammunition is also loaded to higher pressure. Accoring to SAAMI, "The .223 Remington is rated for a maximum of 50,000 CUP while the 5.56mm is rated for 60,000 CUP. That extra 10,000 CUP is likely sufficient to cause a failure in a chamber that's only rated for the "sporting" .223 Remington."

About the Author

Matt Kirkpatrick is a technical communication consultant specializing in firearms training and documentation. He has 20 years of military experience, including deployments to Afghanistan and Bosnia and has trained soldiers and police officers across Canada and internationally for more than 10 years.

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