One other trick that I have done when regulating the sights on my flintlocks is to paint the rear of the sight (I use white out)...What you want to do is paint up to the level that you are thinking about filing off...For example, leave about 1/8 inch of the top of the sight unpainted....Now go back and shoot, using the level of the paint as the top of your front sight...This gives you a reference as to how taking off that much of the front sight will move your group...Then when you file, just file down to the paint...

Like Cay mentioned, you might want to bump the charge up a bit for whitetails...
I have my .54 set to shoot about 1 inch high at 50 yards with 80 grains and when I drop down to a half charge it hits dead on at 25, so I can use this reduced charge for squirrel hunting...