And of course, add your strength bonus, because in those die ranges, they would be slightly different. This is because with a bow, you can over-draw slightly, and the arrow goes faster and hits harder, BUT every bow normally has a range of pull, like you can't pull a 20 lb bow with 100 lbs, it will snap. Likewise, you can't pull a 50 lb bow with 20 lbs and get enough travel on the arrow for it to really work; the string will almost seem rigid.
There's all sorts of bows, recurve, english long, japanese bows, Sumerian bows, etc. But most fit the basic mechanics I laid out. The Bow listed in the OP might be considered a 17-20 strength bow.