Is there a way to decrease the fps on my ghk m4 aeg to gbb conversion kit. out of the box it shoots 350fps at temperatures of 20c. The site I use are being a pain and want me to drop the fps down to the 330-340fps mar, it's not alot but as far as I know you can't get a npas for this gearbox. Does anyone know of a way to get me to that 330fps mark?
Thanks Adam