I usually make two trips to the range to find a load for a rifle. 1st trip, I load 6 of each load plus two fouler shots. That way, I try to find promise in a load. I shoot one group at 100 yards, then another shot of 3 at 200 yards for each load. I then will take the two best loads and load up 12 of each and go back the the range shooting mostly at 200-300 yards. I myself find it hard to keep my concentration for more than 40 shots at a sitting. Espeically for anything kicking harder than say a 450 marlin or 300win mag.