The "Reloading Pages of M.D. Smith" (online) list a .308 diameter 158-160 grain LRNFP or RN (Cowboy Load) using H4895 or H4195. Starting velocities are in the 1350 and 1400 range. There are also some 152-155 grain loads listed (nothing specific for 156 grains, however, but you might be able to extrapolate from those).