The only way to truly train is in extreme stress mode. As I posted before, ya think you're good on the range. Try running at the hardest you can run for at least a mile then pick up your weapon and hit the 3-5-7 yrd line. Stress your body, get that adrenalin pumping, then see how good you are at hitting silhouettes on stationary targets.
With that said, I'm to old to run a mile but have trained over the years at times in heavy stressful scenarios. Hope when the SHTF I can perform accordingly. My life will depend on it.