Yeah, what the topic says. game starts okay, the opening cut scene plays out. I am in the chopper with the gun in front of me but there is no ammunition. we just fly about till we get shot down.

is there any fix for this?

I am on Win 7 PC

The chopper does not require ammunition. Have you tried pressing the fire button? Check the control options to see if it is bound to the right key or mouse button.