They are nice rifles. And good shooters also. I have both the percussion model with a 1-66 twist and the flintlock model with the 1-48 twist. Both are excellent roundball shooters.

I found mine likes 85 grains of 2f Goex and a .490 ball with a .018 patch. I too looked for them in .54 caliber but did not find one. So I purchased what I did. Good luck in your search. I personally would stick with the flintlocks... nice fast lock.