Smokeless Powders: Introduction

In the last several months, we have studied the production of various forms of black powder in depth. The next series of posts will deal with an in-depth study of smokeless powders. We had studied about this some years ago, but not really in detail.

So why smokeless powder?? First, let's go over some disadvantages of black powder:

1. It is very flammable. Black powder can easily be ignited by a single stray spark, hard impact or a hot object and therefore, it requires careful handling.
2. It leaves a lot of residue behind, which can cause fouling problems inside the firearm. The residue is also caustic, which can cause corrosion issues if it is not removed quickly. What this means is that firearms that use black powder need to be cleaned after firing just a few shots. 
3. Black powder also produces a lot of smoke upon ignition. In fact, many infantry troops using black powder weapons faced a problem on the battlefield in that after firing a few shots, they would no longer be able to see the enemy due to the clouds of smoke produced by their own weapons.
4. Black powder is hygroscopic (i.e.) it absorbs water from the atmosphere. This causes two problems: the first is that presence of water makes the powder less efficient and may even spoil it to the point where it doesn't ignite reliably. The second problem is that remnants of black powder in a firearm can cause the metal to rust rapidly. Due to this, it was necessary to clean firearms thoroughly immediately after use, especially in humid areas, in order to prevent the formation of rust.
5. Black powder does not ignite when wet. This caused many soldiers to have their firearms rendered useless during rainstorms. This is the reason why many soldiers also carried a sword or a spear as a backup weapon.

By contrast, smokeless powders offer more propulsive power than the same weight of black powder and leave a lot less smoke and residue behind. This makes it possible to not only increase the range of firearms, but also shoot for longer periods of time without cleaning the weapon -- this is what made it possible to develop semi-automatic and automatic firearms. Early smokeless powders were somewhat unstable, but as technology improved, they became a lot more stable than black powder and don't require as much careful handling. They are also not affected by rainy weather and can even ignite underwater. 

With that said, there are a few misnomers about smokeless powder that we should clear up before we go in-depth with our study. First, the name is misleading: smokeless powder is not actually 100% smokeless. There is some smoke produced, but it is much less than that produced by black powder. The second misnomer is that there is no single formula for smokeless powder. In fact, there are multiple types of smokeless powders, each made with different chemicals. This is unlike black powder, where the three ingredients are always carbon, sulfur and potassium nitrate (albeit with different proportions of the ingredients and different grain sizes).

In our next post, we will study the first development in the family of smokeless powders: guncotton.