When you hear the term Speed Loader it seems to imply you are off to the races. In reality what they generally do is either make putting ammunition into the magazine easier or quickly fill the cylinder of a revolver. Generally a magazine speed loader depresses the follower and spring against the floor plate of the magazine. They come in all shapes and sizes depending upon whether they are an aftermarket item or came with the firearm and magazine. The Glock speed loader is nothing more than a plastic piece which fits tightly over the magazine and has a leg to depress the follower. It allows you to do the work with your hand instead of your thumb. The Ruger speed loader from the SR9C is very similar, but stamped out of flat steel and bent. Some of the aftermarket loaders have more ergonomic designs, but I would suggest if you don’t have a loader to do some research online to find the one which will work best with the magazine you are going to work with. We actually have about five magazine loaders in various sizes because I have several different firearms which use magazines.
Now a revolver speed loader is a device you fill with ammunition and then with a twist or push you release the ammunition into the cylinder. For that reason these are not universal. So if you have different makes, models or calibers chances are each will require a different speed loader. I’ve had wheel guns for years and unless you are shooting in some sort of competition or need the ammo as backup, I don’t really see the need for a speed loader. Sure it speeds things up at the range, but how long does it really take to shove six rounds into a cylinder. They are nice to have, but certainly not required.
So there’s a nickel overview of speed loaders. My opinion is if you have a magazine, you need a loader. At some point your thumbs will be tired of doing all the work. However if you have a revolver you probably do not need a speed loader. For my home defense .357 magnum I do have the firearm loaded and a speed loader nearby, but the only place I have used it in the past 21 years is at the range.