I would say first practice and practice more. I you can set your gun on the coffee table every evening and load and unload snap caps with the speed loaders. Load them left handed, right handed, siting, standing laying down, squatting, eye closed, etc.
Muscle memory take thousands of repetitions to build and ingrain.
5-357rds is pretty deadly 1 in the chest cavity is pretty life threatening.
Statistically most "shoot outs" are not really shoot outs. Most people will get the hell out of dodge when they start hearing gun shots. Not to really on that but the odds are that you will not really be exchanging tons of rds. Especially you you make them count and do not waste them.