The powder burn rate chart can be tricky. Two powders like #9 and 4100 made by the same company will always show up in the same order, they were developed to be different.

Other powders like 4227 and mp300 can be confusing. You can often look at different charts by different manufacturers and the positions will be swapped. Not uncommon that the same manufacturer or publisher will still swap positions over the years. My opinion from use is that MP300 is closer to 296/H110 than 4227.

Good examples are 296/H110 or 231/HP38 that are exactly the same powder. They often swap positions or have other powders in between. Some of that has stopped now that Hodgdon owns everything, but the charts aren’t any more reliable.

Balance what’s in manuals against what people report as good working loads. It’s always a crapshoot.

The burn rates change due to case capacity also & sometimes quite substantially. I have verified this by pressure testing.