The Complete History of Small Arms Ammunition and Cartridges

The Complete History of Small Arms Ammunition and Cartridges

Sam Bocetta

I recently wrote a short history of body armor article for Small Wars Journal where I pointed out that there has long been an “arms race” between two different types of military technology - ammunition and the protection against it. Today I want to deal with the other side of the story and take you through the history of ammunition for small arms.

Every historian looks for an overarching narrative when writing their histories and fortunately when talking about small arms ammunition one is immediately apparent - ammunition gets more powerful with every passing year.

In the early years the race was to produce small arms ammunition with just enough power to hit the enemy and do some damage. This changed sometime in the 1800s when the first recognizably “modern” ammunition appeared.

The race for greater and greater power has continued. As I pointed out in my article on body armor, this is partially because ever more powerful rounds have been required to penetrate protective gear. Alongside this there has been an increasing emphasis on hitting targets from extreme ranges and this has led to the development of extremely powerful bullets.

To understand small arms ammunition of the modern era we first need to look back at where it all started.

The First Ammunition

In the first firearms the propellant and bullet were loaded into the gun separately – just think of the cannons used on ships until the 1800s. Whilst a cannonball can technically be called “ammunition”, I suppose, the first truly integrated types of small arms ammunition date to the 1500s.

There is some evidence that the first paper cartridges were in use as early as the 14^th Century, but they didn’t become widely used until the 17^th Century. Their design remained remarkably stable throughout this period consisting of black powder and a rifle ball encased in paper. It’s a little-known fact that “cartridge” paper, now commonly used for drawing rather than ammunition, gets its name from these early cartridges.

These paper cartridges were used with muzzle-loading guns and sound like they were a real hassle to use! To fire a shot a soldier had to rip or bite off the end of the paper cartridge then pour the powder down into his gun. The ball was then rammed down on top. In theory the paper was supposed to be discarded, but in practice most soldiers used it as wadding to improve the power of their weapon.

After all that, priming powder still needed to be poured into the barrel, as the main charge was not volatile enough to ignite on its own. The musket was then – finally! – fired by a lit match or, later, a flint hammer mechanism.

The Percussion Cap

The invention of the percussion cap revolutionized small arms ammunition. It was first tested by the British, at Woolwich in 1834. By using a combination of more easily flammable chemicals the percussion cap ignited when given a sharp blow in a particular place. This obviated the need for soldiers to carry matches and flints and greatly improved the reliability of small arms ammunition - especially in wet conditions.

Though the advantages of the percussion cap were obvious, it would take 25 years for the British Army to adopt them. From 1842 they started to adapt the Brown Bess – the standard infantry rifle of the day – to take percussion cap ammunition. This was achieved by replacing the pan that once held priming powder with a nipple that struck the new cartridges.

This new design required soldiers to place the round next to the hammer mechanism - which accidentally brought about the next big transformation in firearm technology – breech loading. A huge advance over the complex procedure of muzzle-loading, once the advantages of the new system were recognized it was applied to every type of firearm - from military rifles to civilian revolvers.

In the early years of the percussion cap, however, some engineers identified a problem. The new rounds were surrounded by a metal case that held the priming powder and propellant together. This case had to be ejected from the rifle before a new round could be loaded, complicating the mechanism of these guns.

Many people tried to overcome this problem in various ways. Some designed complicated ejection devices, but these were prone to jamming. Some said that “self-consuming” cartridges should be used, which destroyed the cartridge case when it was fired - but these also proved ineffective. In the end, the consensus was the advantages of metal cases outweighed the occasional jamming problems - and it is this design that is still used for small arms ammunition.

Integrated Cartridges

The next huge advance in small arms ammunition was the introduction of the integrated cartridge, where all the components of the ammo – the percussion cap, the propellant, and the bullet itself – where built into a single unit.

The very first integrated cartridge was made in 1808 by the Swiss gunsmith Jean Samuel Pauly, working with the French gunsmith François Prélat. This cartridge set the standard for all following small arms ammunition. It used a centrally-placed needle to fire and this “centerfire” arrangement is still seen on the majority of cartridges today.

The invention of the integrated cartridge brought two great advantages. The first was since all components of ammunition were contained within a single unit they could be produced away from the battlefield- giving rise to the ammunition industry we see today.

The second advantage was that the new cartridges had a case which expanded as the round was fired. This stopped hot gases from escaping backward through the breech of the weapon, reducing wear on the gun and improving power simultaneously.

The American Civil War saw many military firsts - including the first widespread use of integrated metal cartridges. In the early years of the war soldiers generally relied on their own, muzzle-loading guns. However, by 1864 the Sharps rifle, a breech-loading rifle that used integrated cartridges, was being issued to troops on both sides of the war.

In addition, during the war Smith and Wesson produced the first revolvers, initially as side-arms for cavalry troops. These also used integrated cartridges, and led to the post-war adoption of this type of ammunition among the civilian population. By the 1870s, they were in widespread use.

The First “Modern” Cartridges

Though the cartridge developed by Pauly in the first decades of the 19^th Century was technically an integrated, center-fire, all-metallic cartridge, it didn’t look much like the ammo of today. The first truly modern cartridge was patented in Paris in 1846 by Benjamin Houllier.

This cartridge was patented in both rimfire and center-fire variants, and used either copper or brass casings. It was the first all-metallic cartridge to become popular, and therefore forms the basis of many modern rounds.

1857 saw the arrival, finally, of a cartridge that we are still using today. The .22 short, a rimfire cartridge, was first designed for the Smith and Wesson Model 1 revolver. The success of this weapon led to many imitations, and for years Smith and Wesson were involved in lawsuits over supposed copyright infringement. However, these imitations led to the almost universal adoption of all-metallic cartridges by 1870.

By this date, the basic design of ammunition had been almost universally agreed upon. From this point forward, almost all small arms ammunition would be integrated, metallic, and make use of a percussion cap. Though rimfire cartridges are still used to this day, the vast majority of ammunition, since 1900, has been center-fire.

The 20^th Century Arms Race

Though a standard design for cartridges had been agreed upon, this did not mean that development of small arms ammunition ceased. In fact, the 20^th Century saw the fastest pace of small arms ammunition development to that point.

Though, in general, no great strides were made in the way in which bullets were designed or made, one clear story is discernible in the 20^th Century. Cartridges became more and more powerful throughout the Century. The World Wars of the early part of the period led to militaries adopting ever more powerful rounds for small arms, and the increasing effectiveness of body armor meant more power was needed to take out targets.

Here, I don’t have the time to go through every single cartridge that was developed. However, the process arguably culminated in the development of the 7.62×51mm NATO round in the 1950s. Introduced originally in the M14 machine gun, it was later adopted by militaries all over the world as the standard full-power assault rifle round.

The 7.62mm represented the limit of what soldiers could be expected to carry in the field, and was therefore always a compromise between power and mobility. Though some even larger cartridges were tested, and some are used for snipers and other situations in which more power is required, this bullet still represents the peak of cartridge power.

That said, as the 20^th Century progressed, increasing numbers of civilians, mainly in the US, started to carry their own handguns. This led to certain, smaller calibers becoming very popular. Notably, the 9mm cartridge was raised from relative obscurity to become the most popular round used in handguns today.

And as the civilian market expanded and diversified, it gave rise to a huge variety of small arms ammunition. Though the military tends to stick to pretty standard rounds, because this makes logistics easier, hunters and competitive shooters have no such worries, and have driven a huge diversification of bullet types and calibers, to the point that today the range of ammunition available is truly staggering. Look at any website where you can buy ammo online, and the options are almost endless. This is even before you get into making your own bullets, which is becoming increasingly popular, and allows shooters to customize their rounds to their heart’s content.

The Future

The future is always hard to predict. However, this humble historian is even more confused than normal when it comes to predicting the future of small arms ammunition. This is because the civilian market seems to be diverging from the militaries requirements.

Let me explain. In recent years, hunters have increasingly been drawn to larger and larger rounds. Whether this is because deer are getting bigger, or some people just think that bigger bullets are macho, I don’t know! However, the movement in this market is clear, and at the moment has culminated in the .450 Bushmaster, a large round developed to kill large game at impressive distances.

On the other hand, the military seem to be moving in the opposite direction, toward smaller caliber rounds. For example, the new IAR weapon, the M27, that is currently being issued to US Marines, uses the 5.56mm round, smaller than the 7.62mm round it replaces. It seems that, at least over the past decade, the centuries-long drive toward ever-more powerful rounds has been partially reversed.

The reasons for this is clear enough – on the modern battlefield, mobility is prized over firepower. As I said in my article about body armor, the newest body armor actually offers less protection than the item it replaces, but allows troops to be more mobile. In this context, it seems that small arms ammunition is also getting smaller, and the military is even doing research on how to save even more weight.

For this reason, it may be that in years to come we look back at a lot of modern ammunition as ridiculously overpowered! If that’s the case, the story of small arms ammunition might turn out to be more complicated than even I thought.