bulldawg,

Sure you can use regular black powder in an in-line. In fact, you can use Black powder, pyrodex,pyrodex pellets, ClearShot, CleanShot (or American Pioneer Powder as it's known now), or the new Hodgdon Triple 7. These all have different characteristics and experimenting with them just gives you more reasons to go shooting!

And if you get a .50cal rifle, 2fg is the usual standard to use. A .45cal usually calls for 2fg as well, but some prefer to use reduced loads of 3fg.

"Every moving thing that liveth, I give unto you as meat" (Gen 9:3)

Trust God..........but keep your powder dry!