I expect to only need to fire it once. Shooting at an indoor range helps compensate for the flash effects - practice, practice, practice.
Not to beat a dead horse, but really, have you ever fired a magnum pistol indoors? Most of us HAVE NOT, because of the sound and the flash. It is DEAFENING! Just for fun, practice a few times without ear protection. (Please don't!-I'm just saying it is incredible.)
Anyway, stay safe! In an emergency situation when seconds counts, police are only minutes away...
Take care