Recently bought a used New England Firearms Huntsman 50cal. In line muzzleloders. I purchased the replacement breech plug that takes 209 primers directly with no carrier. It came with the manual and it gives you a couple of different loads for it but I cant find the grain bullets they reccomend. 250 and 300 grain. Bullets seem to be the standard. Can I shoot these safely out of my gun with pyrodex pellets? Even though the book doesnt state it.