FPS will vary depending on the BB weight you are using because the kinetic energy your airsoft gun produces will always be the same. If you are using a .20g BB in your gun you could be shooting 380FPS, but if you change to .25g BB, your gun will be shooting at 340FPS. You will need to contact your games organisers for FPS limit, rules and regulations as these will change depending on the game or area you are playing.
Why is FPS so important?
All airsoft fields will have an FPS limit and these limits can vary depending on the site and where in the world you are playing. These limits are set for the safety of you and other players. If everyone playing was shooting with over the limit guns, this means people could get hurt and as airsoft is a game played for fun, this would take away from the element of the game.
How to change your FPS?
There are different ways you can approach this but the first thing to do is replace the spring. This is usually straightforward and allows you to use a softer spring to lower your FPS if your gun is over the limit of your airsoft fields. To know what spring to select, it is best to contact a local store who will be able to assist with this. You won’t have to upgrade the internals of your weapon when lowering the FPS, only if you wish to increase the FPS.
Another way to change your FPS is to purchase another weapon, this could be expensive, but it is not uncommon for players of airsoft to have multiple guns. Having a different weapon for different set-ups allows you to play at optimum FPS for the field you are playing at.