the little allen screw in the back prevents the big ass flat head spring guide from unscrewing if i remember correctly. if you don't losen that allen screw in the back when you turn that spring guide you can screw things up.
and while i'm posting i find a 15fps variation while using a G&G striker spring, also most of my adjustment happens in 3/4 a turn from full to not enough power to shoot the bb to my chrony
