The above reason ^ is why I use Winchester White Box in 125 gr. JHP .38 Spl. +P and 147 gr. JHP 9mm. JHP for carry and my practice round. At the low price, I don't have to shoot the 'good stuff' for carry, and some 'cheap stuff' for practice. I have seen tests of Winchester White Box, and it's not bad! It will do the job, with proper placement of your shots. I believe you should practice with what you carry, so that you will know what to expect.
All the so called 'Experts' debate using designer ammo for self defense, but, I say the old 'plain Jane' ammo, that has worked well in the past......still can do the job! I still use common guns (S&W Revolvers and Ruger Semi-Autos) in med. calibers. It just makes sense to me. BUT......I don't claim to be an 'Expert'......either!!!!! Bob