Allow me to first state, that using my info is at your own risk.
It would make sense that the Federal NPE (New Primed Empty) hulls are using Federal primers. If I were starting out fresh, I'd look for a load that is also using Federal primers.
The hull is simply a vessel which contains all the elements. Once you've found a recipe that indicates a pressure you're comfortable with, determine if that recipe allows you to get a satisfactory charge which will crimp well.
My experience finds that paper likes an 8 point folded crimp better than 6 point.
Since The paper 16ga hulls I load are for early guns, with 2 3/8" chambers. I start by trimming my hulls with a 2 1/2" shell being the final product the goal. The recipe you like may call for some primer other than the Federal, so re-prime them first, then drop your powder and shot on a lightly compressed wad. If your charge of powder, wad and shot gives you a column that crimps well, it's fair to assume this load will be in the general vicinity of the pressure given for the recipe you're following.
I use an SG16 wad, and 7625 powder, which won't help you unless you're got a stash of 7625. I drop 7/8oz of shot. This charge gives me adequate freeboard to fold crimp, but I also like a roll crimped paper shell. Without further trimming, the rolled crimp is slightly (less than 1/16") higher than normal. I've never found the height of the roll crimp to affect the pressure, but do find that rolled crimps, in general, yield lower pressures than folded crimps.
I'm sure I've forgotten some other details, but I think I've covered the details which affect pressure.
|