First thing to check is if it is the "New Formulation" or the old formulation. A few years back they changed the powder composition a bit but kept the same name. The new formulation also said on the jug "Not For Handguns" (or something similar). MAKE SURE TO USE A SCALE TO WEIGH WHAT THE LOADER IS ACTUALLY DROPPING! The bushing indicated is, as always only a close, usually, guess. With the two formulations, they will come up with different weights from the same bushing because of density differences between the two formulations.
That said, yes Nitro 100 is a very fast burning powder and is entirely useable for light loads in 12 Ga. I use it for my 7/8 Oz. loads. I currently have the "New Formulation" powder. You will have to see just which formulation you have and check loading info that matches your formulation. My loads will use around 17 Gr, (I go a few tenths heavier in the cold weather) with a Win 209 and a Claybuster (8 petal) Lightening wad in a STS or Gun Club case. I will also use the same load in a Top Gun case for one or two reloads. Some people say it doesn't work in a Top Gun but with the heavier loads around 17.3 to 5, I get results more than adequate at 16 Yd practice.
