Don't worry about the shooting test, it's a piece of cake.
Hopefully, you have opportunity to make sure your gun is reliable before qualifying with it. If the very unlikely event that it jams or fails to fire for some reason, your instructor should let you clear between strings of fire. This happened to me (forgot to charge the gun before a string of fire
) and I simply didn't get to make those 3 shots. I still passed with a 235.