What in the Name of Hell IS an Assault Rifle Anyway? Part 2 – From WW2 to the AR15
Posted By Randy on January 22, 2013

Ammunition comparison (cartridges shown larger than actual size, and for relative size comparison only – note that the 5.56 x 45mm NATO cartridge fired by the AR15 has a bullet diameter of .223 inch as opposed to .30 inch for the other three shown here ). You’ll want to refer back to this picture as you read what follows. Left to right: 5.56 x 45mm NATO (AR15/M16), 7.62 x 39mm (AK47), 7.62 x 51mm NATO (M14/FAL), and .30-06 (M1 Garand)
Yesterday we looked at how lessons learned in the course of World War 2, the ingenuity of German military weapon designers, and the whims of Adolf Hitler gave birth to the first “assault rifle”. In bestowing the name, Hitler was referring to the concept of “assault” in the military meaning. As in assaulting an enemy position. Combat, particularly on the Eastern Front had shown that, in the absence of mitigating circumstances, victory generally went to the side that could bring the most firepower to bear, and that was the most mobile in positioning their forces to deliver it. In this, the assault rifle was ideal. Instead of deploying infantry armed with bolt action rifles, supported by a small number of heavy and less mobile machine guns (fully automatic and capable of delivering heavy covering fire in an assault, but nowhere near as portable as an individual soldier’s weapon), every member of an attacking force could be equipped with a handy, compact rifle with which he could deliver accurate, aimed fire in semi-automatic mode out to at least 600 meters, and with the flip of a switch provide withering fully automatic fire when covering or defensive action was called for.
In the wake of WWII, a variety of weapon designs emulated the German model, and in the present day, two are most prominent – derivatives of the U. S. designed AR15, and those of the Russian designed AK47. Because of all the media attention on the AR15 at the moment, I will focus today on that particular rifle, and in doing that we’re going to have to delve into history once again.
The dropping of nuclear weapons on Japan in 1945 simultaneously ended WW2 and marked the beginning of the nuclear era. This, and the opportunistic scrabbling over the scraps of war torn Europe by former eastern and western allies, plunged the world into decades of “Cold War”. Militaries now took time to re-evaluate the realities of combat on battlefields that might include wonderful things like nuclear weapons delivered by artillery shell, and street by street fighting in the radioactive ruins of what had once been cities. Yes good reader, there was once a time when this was all envisioned as both possible and likely.
In 1948, the U. S. Army established the Operations Research Office (ORO) to take a realistic look at issues involving the effectiveness of military small arms, and defenses against them. In doing this, they collected data from over 3 million casualty reports out of WW1 (1914 – 1918), WW2 (1939 – 1945), and the Korean Conflict (1950 – 1953), to evaluate the way soldiers were most commonly wounded by bullets and shell fragments.
As documented in this retrospective:
ORO’s investigations revealed that in the overall picture, aimed fire did not seem to have any more important role in creating casualties than randomly fired shots. Marksmanship was not as important as volume. Fire was seldom effectively used beyond 300 meters due to terrain (WWII, Korea) although sharpshooters in WWI frequently saw 1200m shots, and it discovered that most kills occur at 100 meters or less.
From this data, ORO concluded that what the Army needed was a low recoil weapon firing a number of small projectiles so in 1957 the United States Army Continental Army Command (CONARC) sought commercial assistance in the development of a 5.56mm military rifle.
As I mentioned yesterday however, the military mind is notoriously traditional and slow to change. It could, however, accept that U. S. experience in WW2 had exposed the shortcomings inherent in the design of the M1 Garand rifle leading, in 1945, to the offering up of prototype rifle T25, representing a step forward on the Garand concept. This rifle was also designed to fire the new and equally experimental cartridge T65 – a shortened version of the old standby .30-06 that retained ballistic and energy properties of the old war horse through use of a newly developed powder. While shorter in overall length than the .30-06, the T65 was still a full powered rifle round of the old school that went on to be adopted by member countries of the North Atlantic Treaty Organization (NATO) as the 7.62 x 51mm NATO cartridge. The cartridge is still popular in military and police marksman circles as an accurate and hard hitting sniper round, and in its civilian version – .308 Winchester – as a commonly chosen load for the hunting of big game.
You will note from the photo that the design of the T25 shared traits in common with the assault rifle concept that originated in WW2 Germany – the straight stock necessitating elevated sights (shown folded down in this illustration), the pistol grip to afford comfortable access to the controls without requiring that the operator be double jointed, that it employed a 20 round detachable and quickly changeable box magazine (not shown here), and the fact that it was selective fire, it was not an assault rifle. While the T25 shared these attributes, it shared others with the battle rifles of old that were considered to be of great importance to its designers – it was not particularly compact having considerable solidity and heft, its manufacture relied heavily on precision machined and forged steel parts, and it fired a full powered cartridge. This last made firing it in full automatic mode a potentially dental filling loosening experience which the straight line design of the stock would assist in making more controllable.
The T25 evolved in development into the T47 (right), in which format it went on to be adopted as the standard U. S. military issue M14 service rifle from 1959 to 1970, and continues to be issued for special applications to this day. You will note from the photo that the biggest visible change in the design is the reversion to a more traditional style of stock.
By comparison, Commonwealth countries, including Canada, adopted the Belgian FAL standing for Fusil Automatique Léger (Light Automatic Rifle) that, like the U. S. M14, fired the 7.62 x 51mm NATO cartridge from a 20 round magazine. Like the T25 prototype, it shared physical attributes in common with the assault rifle concept, and all the same ones in common with old school service rifles. In Canada, the basic FN C1A1 had no selective fire capability and fired strictly in the semi-automatic mode. A slightly heavier version, the C2A1 was selective fire, and issued to serve the role of a squad automatic weapon in support of infantry teams as a light machine gun, but most Canadian soldiers carried the semi-automatic only version.
It was weapons like these that equipped NATO armies while the U. S. Army was in quest of that 5.56mm light rifle we were talking about at the outset of this article. Skimming off all the boring details, suffice it to say that the winner of developmental trials was the “Armalite Rifle Model 15” or AR15, submitted by the Armalite Division of the Fairchild Engine and Airplane Corporation. Adopted by the United States as the Rifle M16, and supplanting the M14 in general service in 1970, the design of the M16 incorporated proven features from successful designs elsewhere, and its manufacture was conceived at the outset to be highly automated; i. e., it was faster and less expensive to build in quantity. The M16 was the first true assault rifle to be adopted by the United States (The AK47 – another true assault rifle, inspired by study of captured German StG44 rifles – had been an item of general issue in Warsaw Pact nations since 1949), and it has since evolved from the balky and temperamental M16 into a mature and reliable weapon that is the service rifle of choice for many modern military forces, including Canada where it is issued in a number of variants based on the C7 (full size rifle) and C8 (carbine) platform. While externally similar to the M16 family, the C7 and C8 are completely re-engineered weapons incorporating changes in design intended to make it more suitable to Canadian military realities. Retaining an external envelope – the chassis if you will – conforming with that of general issue weapons used by allies ensures, at least to some respect, the interchangeability between forces of external attachments important to the modern battlefield, such as optical sights, target designators, rifle grenade launchers, visible light and infrared illuminators.
So far we’ve looked exclusively at how the wandering path through the vagaries of history brought the military weapon that can legitimately be called an assault rifle from the StG44 of 1944 to the M16 of the present day. It should not be missed by the reader that the candidate rifle submitted all those years ago for possible adoption as the next U. S. service rifle under the mandate of the ORO bore the designation AR15, and was originally designed exclusively as a military concept to address anticipated military realities. Not least of these was as a lightweight “bail out” rifle for attachment to the ejection seats of military aircraft to provide a more powerful and longer reaching weapon for downed aircrew than was afforded by the pistols with which they were traditionally armed.
Lest the fact that the initial conception of the AR15 was a strictly military one be misinterpreted, let it not be forgotten that there is now, and has always been, significant overlap in both directions where the development of both sporting and military arms is concerned, and in some cases the only difference between those offered for purchase by civilians, and those acquired by governments for military issue, is the cosmetics. For example, a military issue 9mm Browning service pistol will normally have a rougher, less finished appearance, and will wear a robust, low maintenance, non-reflective, corrosion resistant finish more conducive to life in the field, while the same pistol offered by the manufacturer for the civilian market will be much more polished, beautifully blued, will be offered with a variety of sight options, and be generally prettier by comparison. Nevertheless, they are the same gun.
There are also cases in which there is no actual difference between the military and civilian versions of the same firearm. For example, for some manufacturers, there is no difference between a bolt action hunting rifle designed to take big game in situations where long range shooting is required, and a military sniper rifle built in the same factory. Of course, prettier versions of the same rifle will be available for people who like shiny things, but in fact, the military version can be purchased by civilians, and will be preferred by some because of the utilitarian finish, plastic stock, and general resistance to breakage when knocking about exposed to the elements. It is this virtually indestructible robustness that first attracted me to my own favourite big game hunting rifle: a bolt action Lee Enfield No.5 Mk.1 “Jungle” Carbine – a shorter and lighter variant of the standard Commonwealth issue No. 4 Mk. 1 rifle, developed as a handier rifle for troops operating in hot climates, and briefly considered as a general issue replacement for the No. 4 Mk. 1 before adoption of the semi-automatic FAL by everybody in the Commonwealth. Built in 1946, my rifle is exactly as it would have been if issued in service (mine was unissued and so appears as new except for the mileage I’ve put on it), and in preferring to field a Lee Enfield I am far from unique because it remains the rifle of choice for many a Canadian hunter. The venerable .303 British rifle cartridge, fired from the tried and tested Lee Enfield action, has taken game on every continent, and they don’t come any tougher, more reliable, or more accurate in the hands of a true marksman.
Then there are the cases where significant differences exist between versions of a firearm intended for military use, and those developed for sale to the civilian market. So it is with the AR15 and its clones. After Armalite sold its rights to the AR15 design to Colt Manufacturing in 1959, the latter began marketing its semi-automatic only versions of the rifle exclusively under the designation AR15. The patent on the design having since expired, the marketplace is now full of companies building and marketing their own versions – hence AR15 “clones” – along with a staggering array of after market accessories. The press has made much of this rifle’s popularity – mostly negative – and opinions are being loudly expressed by people proclaiming that only the sociopathic and deranged would find any kind of attraction to owning such a tool of destruction, the very design of which renders it inherently more “powerful” and capable of dealing out more death and destruction than anything ever seen before.
We’ll take a look at this interest – positive, negative, legal, and political – next time. You might learn a few things that will surprise you.
Excellent article! I've used a few of these, and I've actually written a paper on the evolution of military rifles. However, you just taught me several things I had missed. As usual, nicely done!
Thank you Arthur. That’s high praise indeed! I would be interested in reading that paper some time, and also in learning what new insights I've given you.
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