well you can always do this, if you haven't figured it out or still care
under the class CfgWeapons add these lines
revolving=" ";
revolvingAxis=" ";
go to Klinks tutorial:
http://www.dc3d.co.nz/tutorials/canopies.htm , and go to how he made a plane's canopy open.
Ok, now the component you want to move you put the name of it inside the " " of:
revolving=" ";
Now put the name of the point you made after making that pivot point, or center point or whatever its called. In Klinks tutorial lines 6a-6e. You put that points name in
revolvingAxis=" ";
Now when you fire your gun it should rotate\move whatever component you want.