Will using a 9.6v in my airsoft gun increase fps?

Question

My m14 already shoots about 330 fps and I use a mini 8.4 1100 mah.

so if I upgraded batteries, will it increase fps or just the rate of fire?

Answer 1

No

It will make the motor spin faster.  The spring makes its FPS increase.

Answer 2

It will increase ROF and increase the speed at which the motor wears out...