I am with Jimro "Accurate charge weight does not always equal accurate ammo".
If you have an accurate load, verified with something like the OCW method, you can almost ignore the charge-to-charge differences in weight of powder.
I got to the point of not weighing most of my loads for 600 yards - still shot 2-3 MOA with a service rifle (M14).
And Edward, don't let your wife catch you doing "sex dumps" when she thinks you are reloading - she will never trust you again!
... still waiting for that stimulus to kick in ...