I am guessing that your bullets are not yet moving when you are setting the angle of motion ? If they have zero motion (velocity) then they cannot have an angle of motion. This was the explanation I got
"The bullet's angle of motion is based on it's x and y velocity. If a bullet isn't moving then what is it's angle of motion? Think about it.
And you have the bullet property 'set angle' = 'yes' - "Set the objects angle to the angle of motion".
So when the bullet isn't moving, it's angle of motion = 0 and it's angle gets set to 0."
This lesson was provided by ramones ...
"But now I am the master!" (but only a master of evil ?) mmmmmwwwwahahahahahaha
(Sorry, it's early and I am still on my first coffee and have not had my anti-silly pills yet)