bug or is it
 

I have a Balao class with a bow 4inch and 50 cal's on aft when I go to battle stations my team man the 50 cal's not the 4inch gun for shelling ships and I cant get them to do it ! any fixes?

first question: which version of SH4 are you playing, 1.3, 1.4, 1.5, 1.5 with Uboat missions?
second question: are you placing crewmen in the deck gun crew slots before you expect the weapon to fire?

The 1.5 with uboat mission with fotrs installed and yes the crew is in position when I go to battle station they only man the aft 50 cal I try to get them to man the 4inch but the don't

ok, thanks for that.
to the basics....
can you post your JSGME config? that will show what your mod list is and also where you have SH4 installed.
your problem may be related to the installation folder and it may also relate to your save folders.
:Kaleun_Salute:

There aren't any 50cal on the Balao. 20mm?? Did you empty the Save folder before or after activating FotRSU and prior to playing the modded game? Also, in addition to what KaleunMarco says, give us the date and location you sailed from please.

maybe that's it i dont think i did