who made it, dixie gun works? if so, call 'em up tomorrow. chances are it'll either be a 1:60 (patched balls) or 1:48 (patched balls or maxis).
OR, just figure out the twist yerself, it's easy. just take yer ramrod and put a lubed patch on its jag for a relatively tight fit to the barrel's bore, run the jag down 'til it hits the breech plug and stops. wrap a piece of tape on the end of the rod exactly where it meets the muzzle, put a mark on that tape that lines up with the front sight. slowly pull out the rod and take note of how far the rod's end mark rotates. measure the length of the rod from its jag to the tape - that's the rifling's twist.
if the barrel is 28" and the mark rotated exactly one full turn, that's a 1:28 rifling twist, or, the ball/bullet makes one full rotation down the 28" length of the barrel. if the mark rotated about 1/2 turn, that's a 1:56 rifling twist.
as an example, a 31.2" GPR hawken barrel will have a rod rotate a tad less than 1/2, for a rifling twist of about 1:60.