4320 can be tricky. I won't go on here with my extensive experience with it....instead, I recommend you google up Norma Burn Rate Chart. In my opinion, the best chart available to us handloaders, in that it rates powders in two areas, relative velocity AND relative pressure. I'm not aware that any other burn chart does this. When you look at the chart you will note that 4320 is on the faster side of 4895, right down near 3031. And that reflects my own experiences. All the other charts have it up around H380 pretty close to W760. And, with light for caliber bullets, it most likely is. But when you start going off the rez with heavier bullets and changing bore diameters, you will see some amazing velocity progressions on your chronograph. It's an excellent powder, just respect it.
