By grouping I just meant to be able to fire 2-3 shots in a rapid succession to possibly emulate a HD situation. Obviously cant do that in SA.
Well, yes you can, it just takes more practice.
Shooting any gun is going to help with some basics. However, shooting a 22lr is never going to simulate shooting 357mag. You will still have to spend money on your defensive ammo of choice, probably a lot of money.