crazyhorse said:
"...I bought triple 7 ffg. Is there some thing I need to know so I won't damage the rifle or my self?..."
1) Read the 777 info carefully...I don't know personally but have seen several comments that it is not a 1:1 comparison to real BP...more energetic...and that a typical load BP charge should be reduced some when substituting full power charges of 777, etc.
2) The same amount of powder as the caliber is usually fine for plinking around, particularly getting used to a new rifle so you might try that...40/50/60grns are usually good round ball plinking charges for .40/.45/.50/.54/.58/.62cals (and if you use plinking charges like these you won't have to worry about/bother with reducing the charge any as they're already low and safe)
3) Until you get comfortable with what's going on, you might consider wiping the bore after every shot with patches dampened with something like TC #13, or Hoppes No9 PLUS BP, or even damp with water just to keep most of the fouling wiped out and the bore condition the same for every shot.
4) Always ensure the patched ball is sitting down firmly on a powder charge before firing.
5) When you get a load of "powder, patch, and ball" correctly seated, a good thing to do is to create a "witness mark" while the ramrod is still in the bore. A simple way is to wrap a piece of electrical tape around the ramrod so the bottom edge of the tape is flush with the muzzle...that creates a "witness mark" so you'll know at a glance when you make your next reload if you forgot to put in the powder (tape will be lower) or accidently put in two balls (tape will be higher) etc...the witness mark stopping in a different place will tell you something is wrong.
And of course if you change and start using different sise powder charges, then the tape will need to be repositioned to make an accurate witness mark for that new series of powder charges.
6) Very handy items to have are ramrod screw on attachments such as a patch retriever, brush, ball puller, and T-handle (or screw on wooden ball) for your ramrod so you can get a firm grip in case you get it stuck down bore...and if you do, don't just pull it straight back out with gorilla power as the ends of the ramrod can pull off...twist the ramrod clockwise and gradually pull while doing that, etc...