[FOX_111]

There is no way to safely drop the fps of a gun without changing some parts in it.

The velocity reducer is unsafe in high fps and on full auto. The small lips that slow the BB down can break or bend out of shame and allow the BB to go trough at full speed.

Games host should set their fps limit based on joule output. But since almost no one know what 1 joule is, it's done in fps.

A stock 280fps gun give about 0.70 joules with 0.20g BB.
A 400fps gun will output 1.49 joules with .25g

If I set my field limit at 1.49j, no mater what weight of BB you put in your gun, you still have to be under 1.49j. Heavier BB goes slower, but hit with more energy for a longer time (distance).

Here is an example for snipers.
Normal limit for sniper is 1.88j or 450fps with 0.20g. When using 0.30g, the velocity drop to 367fps. Since the 0.30g BB retain it's energy farter, it require a minimum safe engagement distance of 40 feet to be safe. At 40 feets down range, the BB has slowed anough to carry about 1 joule of energy, wich is a standard energy output that is hard enough to sting but not enough to break skin.

1 joule output is equivalent of a hit from a 0.25g BB comming from a 350fps gun at 10 feets.

You now have a good idea on how things work.