I have a .50 cal. caplock T/C Hawken and it has a twist rate of 1:48. That twist rate will work quite well with a patched round ball and such conicals as the T/C Maxiball or the R.E.A.L. bullet. It has been my experience that it will not work with any of the modern plastic sabot bullets. These bullets are simply not stabilized by the 1:48 twist rate and they are wild as all get out. They are all over the paper and some not even on the paper. So, forget using them. Stick with patched round balls and you will have an excellent hunting projectile as well as a good target projectile.
BTW, if those T/C Hawkens are in good shape (good bore, good functioning lock, etc), grab all of them because you can re-sell them for around $350 any time. Clean them up, check them out, lube where necessary and put them up for sale on this forum for $350. Many have sold for that on the forum. If one has a bad bore, don't pay more than $100 for it and then send the barrel off and have it re-bored for a larger caliber. If it is a .50 (which is common for a T/C Hawken) have it rebored to a .54. It will cost around $100 to rebore it. You will have $200 in the gun and you can sell it for $350. That's a tidy profit. Wish I could find a deal like that.