Speed loaders are a required item if you are using mid capacity magazines for your rifles. Certain types may also be helpful for your pistol magazines too. Whatever the case, a speed loader is the lifeline to your gear that you will always use every time you go out and it is often overlooked. If you can make your life easier by getting your magazines loaded up quicker then it is definitely worth it.
Speed loaders work by transferring several BBs from the loader into the magazine with the press of a plunger. You'll be pressing this plunger several times to transfer the BBs into the magazine and you will feel resistance/tension as the magazine gets more full and full.