When I was testing my loads there was quite a large jump in velocity between the loads (because of the small amount of powder). At the time I was having an error rate of about +-/.2grains. So sometimes it would be 4.2grains and sometimes it would be 4.6 grains(when I was aiming for 4.4grains). One was under the PF limit and the other was over. I compromised by using 4.5grains. This gave me a fairly large amount of leeway. It was also good for shooting bowlingpins, which need a fair bit of power to knock over reliably. This way I can use one setting for a number of different games, IPSC, Speed Steel, Bowlingpins etc. I've since fine tuned my press so the error rate is much lower, but I just kept the same charge because I'm used to the recoil now.