It’s funny you mention this. I just built two identical bows spec wise. The first is an Osage riser with bamboo cores, .040 black glass, and a 4 3/4” tip wedge. This bow has black walnut cores with a strip of Core-Flex, .040 green glass and a 4 3/4” tip wedge. The Osage bow was .265 (46@28) and the green bow has .263 (40@28) The Osage bow starts stacking hard between 27-28” but the other draws smoothly out past 28”. I purposely reduced the stack slightly because of the Core-Flex and the extra glue line. I was shooting for 43-45@28 but it’s off more than I expected and the only thing I can figure is the difference between core woods.