Much like how there is a lot of misinformation about the type of “bullets” that most firearms shoot, there is a large amount of variety in airsoft ammo, and some finer points even overlooked points, can impact performance. For example, airsoft BBs can be made to be biodegradable and without seams, among other factors. Here we’re going to take a look at how the size and weight of airsoft BBs will affect performance.

First up is size. There are a number of different sizes in airsoft ammo, most notably being 6mm BBs. 6mm BBs are arguably the most universal of airsoft pellet sizes, although some airsoft guns shoot 8mm BBs instead. The impact that the size of a BB will have on performance is clear and indisputable: you can’t use different sizes interchangeably. That is to say, if your airsoft gun shoots 6mm BBs, you can’t fire 8mm pellets through it. Your mag probably won’t even accept them, and if it does, it won’t feed them into the gun.

That’s the easy part on how size and weight affect the ammo because weight is the more significant portion of the picture. You will find that though you can fire many different weights of BBs through an airsoft gun that accepts 6mm BBs, depending on a few factors like the FPS rating of the airsoft gun, the weight will heavily (no pun intended) impact performance.

Let’s take a look at weight and FPS rating, and in this scenario, we will consider an airsoft gun that, regardless of its method of operation, is rated to fire BBs at around 400 FPS. A muzzle velocity of 400 FPS is neither blazingly fast nor terribly slow, so it’s a rating that a lot of players will probably be able to relate to.

Now consider the fact that you can buy 6mm BBs in weights of .2g, .25g, and higher, even up to .32g. You are likely to be struck with one of two instincts. The first assumption is that the lighter pellet will fly farther, but you also might assume that the heavier pellet will have a more stable ballistic performance; that is that it will be more accurate, more reliable, and hit harder downrange.

In reality, the truth lies somewhere between these two assumptions. While you can shoot lighter pellets through a faster gun, you’ll find that they will work but that the gun will be overpowered for them. At the same time, heavier pellets will be less accurate because they will be too heavy for the power of the gun.

Instead, you want a balance between power and accuracy, and for a gun that can reach 400 FPS, that is somewhere around .25g or .28g. Each airsoft gun has a personality of its own, and so you will need to practice to locate this sweet spot, but with trial and error and patterning you can locate it.

If you want to learn more about the fine points of how airsoft ammo size and more important weight can impact the performance of an airsoft gun, reach out to the professionals at MiR Tactical at There you will find not only a ton of gear but a ton of experience. Give their team a call at 800-581-6620 and they’ll field your questions.

For more information about Airsoft Starter Kit and Airsoft Websites Please visit : MIR Tactical.