I had some jim shockey's powder fffg. I was also using some pyrodex RS powder. Did 60 grain loads on both. Shot great on both, but i prefered the jim shockey's because it burned a lot cleaner. My average load was around 24 grains.
I'm not all that familiar with Jim Shockey's powder. I've tried it, as well as every other synthetic I've come across, but none of them work in my guns. I liked them for target shooting with percussion guns simply because they burned clean, but not in flinter's, and those are all I've owned/shot since about 1990 (I'm limited to black powder in my guns). I never shot anything but pyrodex in my revolver, and never had an issue with it (although it doesn't really burn all that clean). The synthetic powders are harder to ignite than actual black powder is, but that's not an issue with revolvers.
If I remember correctly, the Pyrodex RS is a rifle/shotgun grade, and they have a "P" version for pistols. The P would burn faster (and with a higher pressure) so would be better for pistols and revolvers with their shorter barrels. It's likely that 60gr of the RS isn't going to burn fully, especially in the smaller calibers, so you'd be blowing excess unburned powder out of the barrel. If you can only burn 40gr before the ball leaves, your blowing 20gr out onto the grass... Even if you don't go with a heavy charge, burning the P grade would mean equal effect, but with a smaller powder charge.
The same can be said for the 3F powder. The 3F powder designation is pistol/revolver appropriate, much more-so than 2F would be, especially in the 50 caliber and under bore sizes. Since 3F is finer, it burns faster and generates more pressure, so a smaller charge is again possible, and it's more likely to fully burn in a shorter barrel. A powder charge will also burn faster in a larger caliber barrel than in a smaller caliber barrel.
BTW, if your curious as to whether you're blowing excess powder out of the barrel you can find out easily enough by shooting over a white sheet spread on the ground, or over snow. Blowing excess powder out will give more recoil, but no increase in velocity. It can actually decrease the velocity.