This is why I keep load develop records. If 75 grains gives me x fps and 76 gives me y and so on then when you get a new lot number you drop back a few and shoot. Compare that number with records and work back upto where your accuracy fps was at. It shouldn't take more than 3 or 4 shots if doing it right.
I've had lot # changes vary by 1 or more grains. No big deal.
Kris
I've had lot # changes vary by 1 or more grains. No big deal.
Kris