If I remember correctly, the very early TC Hawkens all had a very fast twist and were designed for the Maxi-ball(bullet). Very accurate, which is one reason most BP matches are patched round ball only unless otherwise noted, specialty marches, stake shoots, etc. you can measure your twist by taking a ramrod, cleaning rod, or " wiping stick", jag and patch. Measure the barrel, mark the muzzle and the rod, then push the rod down to the breech watching for one full turn, should do it twice for a more accurate guess. If you get less than a full turn you have a slower twist. I don't have a conversion chart handy but there is one on line. Btw, my very old (1975) 1st ed. Lyman BP hand book states the .50 cal. Hawken twist is 1:48. Good shooting and keep yer powder dry. I find most of my accuracy problems occur in the brain housing group:)
Hawkdancer