Good question but don't have the answer. I experimented with H110 in 44 mag when I started reloading. I got below 18gr with 240gr bullet and wierd things happened. Like POI changed 6" and wierd ignition. Velocity spreads went to over 200fps. That was over a decade ago, and now understand H110 is not a powder to playing with reduced loads cause pressure drops significantly below 15% max. It really depends on the powder to be honest. RL22 likes to be ignited at high pressures, and they say its pressure curve drops off quickly on reduced loads.