No Ed, I didn't get it backwards. For me, with the ball/patch combinations I use today, i see no difference in fouling between 3F and 2F. Years ago, with the other makes of powders we were using, ie; Curtis&Harvey, Meteor, ICI - some others too) 3f fouled more than 2F. My wife even preferred 2f in her .36 Seneca, as I did in the .36 H. Sharron barrel I tested at one time along with the various .45's, .50's and .58's - all 2F. 3F fouled more than 2F.
Today, in the .40, I use 65gr. 3f or 75gr. of 2F. In the .45, I use 70gr. 3F or 82gr. 2F. These loadings give the same poi and group sizes. There is no difference in fouling noted when loading. I have noticed that when using 2F, I have to prick the pan due to fouling blocking the hole, while 3f doesn't produce fouling that can blocks the vent.
Using 65gr. 2f in the .40 raises the POI by 1 1/2" at 50 yards and doubles the group size. In the .45, using 70gr. 2F double s the group size and lowers the POI by 1" and doubles group size. Raising the 2f charge 10gr. duplicates the lighter 3F charges in both rifles. In the .69, going from 82gr. 3f to 96gr. 2F duplicates the lighter charge for point of impact and speed.