Flintlocks aren't accurate.....

[Kmcmichael]

20gr is too small a charge for a .40 cal., especially at 100m. .40 cal. should be shooting 40gr. +/- 20%. Semper Fi.

I disagree. My regular load is 55gr and I never shot any better than 3” with it. I just tried that load on a lark. I HAVE shot some really good groups at 50 yards with it.
If one can stay away from the transonic region accuracy is better in my experience.
Caveat, my range has a very inconsistent wind due to high berms and being in a hole. The wind seems to affect round balls in that 1500fps + range more than subsonic.

 

[stikshooter]

75 yards!

.54 Hawken Flintlock by Sharps Man, on Flickr

Three shots....not 8-10 and then the others cut away! This rifle continues to amaze me doing this kind of thing. 100 grains KIK 2F powder with a .530 Hornady swaged RB. Oh...I forgot to add....that's 5 shots!

Ain't braggin if you can do it!!!/Ed