Aug 11, 2018 4 min read

I have read it so often that it makes me realize just how many people do not understand how a firearm or round of ammunition works. I might be computer illiterate and I can’t rebuild a lawn tractor but I do know firearms and the ammo they use.

I will try to simplify the reason it is all but impossible for ammo cooked off in a fire to send bullets whizzing about; note I said bullets.

Keep in mind that a cartridge or round of ammo is made up of 4 parts. First is the casing, which holds the whole mix together. In most instances, the casing is made of brass. Next there is a piece of the cartridge called a primer or, in some case, a primer mix. Third, there is the powder in the case and on top of the bullet. Finally, we find what is really the bullet. This is the part of the cartridge that is sent toward the target when it exits the barrel and becomes a free flying projectile.

This is where we unveil a problem for many people who mistakenly call the cartridge a bullet when in reality the bullet is but part of the cartridge. The firearm itself is a platform to control the cartridge of the gun in such a manner that the bullet strikes where intended and also can be made safe when not used. What happens is the firing pin of the gun hits the primer, which in turn throws sparks into the powder, which ignites. The powder burns, building pressure that can reach as high as 60,000 pounds per square inch or psi.

The gases from the burning powder rapidly expands building the pressure high enough to overcome the inertia of the bullet. Once pressure reaches the required level that can range from 5,000 psi to 60,000 psi, the bullet moves down the barrel and exits, hitting whatever it was aimed at.

The reader must understand brass by itself is somewhat pliable but is in no way strong enough to contain even 1,000 psi high pressure. Unseen the high pressures utilized by single rounds does nothing bad to the case and in fact many cases will be reloaded and used over and over. It is the steel that the chamber is made of that prevents the case from coming apart. The brass expands until this expansion is stopped by the steel of the firearm. Without that steel, the brass separates before that bullet moves.

Now let’s look at ammunition cooked off by a fire. It’s very important to understand it is not the brass case that prevents the casing from splitting open or coming apart. It is the steel in the rifle. Since it is enclosed in the firearm, it can’t expand further than the rifle chamber allows. That is the missing key to the whole question of can bullets fly about when they cannot build up the necessary pressure?

Of course not. Long before the pressure to send a bullet down range, the case has split open and the bullet just drops to the ground. An exception to the bullets flying about from a fire is because it was loaded in a firearm and the brass was supported by the walls of the firearms chamber.

It is a fact that gunpowder is very volatile and can add fuel to the fire. There is even the possibility of an explosion if black powder is involved. However, I find myself fearing gasoline more than a fear of fire and gun powder.

So the next time you are watching a house fire and you hear a buzzing past your ears, you don’t have to hit the ground. It is not bullets a flying but more likely a yellow jackets’ nest escaping the fire.

George Block writes a weekly outdoors column for the Observer- Reporter.