Hey thanks for the suggestions,
"If your using the bullet behavior, and has a angle set, the moment you mirror the object, if you apply 700 to the speed should work both ways since the bullet behavior only pushes the object towards its current angle."
This doesn't appear to be true though, if I set the bullet speed to 700 it will only travel to the right no matter what else is happening?
You did send me down the path of playing with the angle of motion rather than the speed though, and i ended up solving the problem by having it set the angle of motion to 0/180 depending on weather it's mirrored. ANd now it appears to be working how i wanted, so thanks for prodding me down the right path.