I know this thread is a bit old, but here’s my .54 J&S Hawken built by John Bergmann in 2010 with parts from Don Stith, who owns the original from which this was copied. It has a .54 cal, 1-56" twist, 36" X 1 1/8" - 1" tapered Rice barrel, RE Davis lock, 14 1/4" inch length of pull, and weighs 10 lbs, 13 oz. It’s very accurate with a .530 ball, 100 gr FFg, and a .015 pillow ticking patch with mink oil.

[Linked Image from i.ibb.co]