Of course the resulting draw weight depends on other factors as well, but I've found for something like a 62" long d/r longbow, with the bamboo thinned to almost 1/8 at the center and almost 1/16 at the tips, an osage core lam .200" parallel thickness from dip to dip(12 inches), then tapering to the tips at a rate of .0035/1", and a parallel osage belly lam of .200" I can make bows in the 50's or low 60's of draw weight.
This is assuming accurate grinding, tapering, and shaping so that there is minimal wood removed during tillering.