I have a 24/7 Pro 9mm, full size. I have not fired +P ammo. I figure if I am in the situation where I am forced to use my self defense rounds, that my Federal HydraShocks will do the job.
The manual says the same thing for mine, I just figure I wont use it. There are other types of ammo that will do the job for different needs. But good luck on your search! Try to google it I guess.