How interchangeable is ammunition?

This comes up now and again, and I haven’t posted a firearm entry for some time, so here’s a new one.

There are several calibers that sound like they should be interchangeable, but the truth is, there are slight differences that can lead to disaster for your fictional characters, and your real life ones.

Revolvers

I touched briefly on what revolvers were.  Now I’m going to dig into them in detail.

Single action revolvers require that the hammer be pulled back by hand in order to cock them.  This can make them much more accurate than a double action, because far less effort is expended to pull the trigger.  On the other hand, they are slower.  The rate of fire isn’t any slower, really, but the reloading time is.

To reload a single action revolver, you open a little gate at the back of the gun.  This is found just below and to one side of the hammer.  It will allow you to see into one chamber at a time.  On the front of the cylinder, under the barrel is a small rod on a spring.  You use this to force the spent casing out of the chamber.

Once the empty is out, a new round can be loaded.  This has to be done for each chamber.  Once all six have been reloaded, the gun is ready for use.

Actions and Reactions

When people talk of guns, they often refer to them by the action the gun uses to prepare the next round to fire.

For centuries, all guns were single shot weapons.  You’d fire once and then have to reload.  If you wanted to fire more than once, you needed to add another barrel.

Until the metal cartridge came along, all guns were muzzle loaders.  That means that the powder and bullet were shoved down the front of the barrel.  The “primer” may have been a piece of flint, or a burning string that the shooter placed in the flash hole by hand, or it may be a modern percussion cap that ignites the charge.  These guns are still called by the method of ignition used: Matchlock, Flintlock, Cap and Ball, and so on.

Other types of single shot actions are: