The Smoke In Smokeless - Brief Article

"But Charlie," you shout, "how can there be smoke? We use smokeless powder." True, but what's that cloudy stuff in the air then?

The first time there was any really dramatic evidence of "cleaner" burning powder was when Winchester introduced improved AA shotgun shells loaded with a new propellant. These powders became known as the "Super" powders (Super Target, Super Field, etc.) and you could easily see that the shotgun bore had less stuff in it.

The problem is that it's very hard to translate that into any practical means of evaluating handgun loads. Gunpowder is pretty simple stuff composed primarily of one or two organic compounds: nitrocellulose and nitroglycerine. Both of those are simple compounds of carbon, hydrogen, oxygen and nitrogen.

Added to it are some other things to deter burning, stabilize the mixture and promote easy flow through metering devices. Additives amount to a very small percentage-- less than 1 percent-- of the whole.

Additives fall into a couple of categories. There are deterrents, such as dibutylphthalate, that serve to slow down burning rates. There are stabilizers, such as diphenylamine, that coat the grains to promote longevity and there are retardants, such as potassium sulfate or nitrate, that reduce muzzle flash. Muzzle flash has become something of a hot button issue, so the powder companies are addressing it.

Nitrocellulose is usually an off-white colored solid; nitroglycerine is a colorless liquid. But most powders are black. True? Graphite is added to most powders to serve as a lubricant, making it flow better in powder dispensers. What's graphite? Carbon. What does it do when stuff around it bums? Nothing, but it sure is black and looks like soot.

Nitrocellulose is made by treating wood or cotton fiber with sulfuric and nitric acids. If this were a perfect world, our gunpowder would bum all the way down to carbon monoxide, carbon dioxide, water and nitrogen gas. Some of what we perceive as smoke is really just water vapor.

While the reloader may choose from nearly 100 canister powders, shooters may not understand that every powder has a range of pressure at which it works best. If pressure is too low, you'll normally have cases come out of the gun very sooty. Sometimes all you have to do make a load bum cleaner is increase it-- but only within published limits.

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