Everything he said is true BUT Do Not use your bullet to compress you black powder with. If you do not have a compression plug as offered by www.buffaloarms.com get a peice of wooden dowling that just fits the dia of your case. Lay your bullet side by side to the wooden dowling and mark where your last driving band just befor the nose of the bullet. Then mark to where you will be seating your bullet depth to. Cut your wooden dowl approx 1" above the mark.smokinjoe5150 said:tanoose, yes you can shoot "Real" powder in the NEF, H&R and B/C.
You'll have to use a blow tube or wipe between shots to maintain the soft fouling needed for accuracy.
If you just want to try it out for fun, try a 500 grain bullet 20:1 or 30:1 alloy sized to .459 using SPG lube in the grooves AND on the bore-ride section. Use enough Goex or Swiss 1 1/2 or 2 f to fill the case so you will get about .1 to .2 compression when the slug is seated. Re: neck tension, .001 to .002 is plenty; no crimp, just size enough to remove the mouth bell.
If you're using the Lee 500 "Postell" style, load to an overall length of 2.87 in the NEF. A Paul Jones Creedmore 535 should be seated to 2.88. This will seat your slug .030 off the lands for starters.
Try Sagebrush for bullets if you don't want to cast your own: