Don't get hung up on the numbers. If the load is accurate, that is all that matters. I am not being smart; many people have discovered that a low SD doesn't nessessarily translate into increased accuracy.
You know the rest. In the books you have read
How the British Regulars fired and fled,
How the farmers gave them ball for ball,
From behind each fence and farmyard wall,
Chasing the redcoats down the lane,
Then crossing the fields to emerge again
Under the trees at the turn of the road,
And only pausing to fire and load.