I'm not exactly sure what weapon speed will give the personal Ranged Attack speed of 1.7-1.9, but that is the ideal RAS for BM Hunters. For MM it's more like 2.3-2.5 so that they can get in their 3:2 or 1:1.5 shot rotations, same with SV.
I do know that the Wolfslayer Sniper Rifle is the second best gun in the game for BM Hunters and it has an attack speed of 2.6, whereas the Sunfury Bow of the Phoenix is much better for MM and SV Hunters with an attack speed of 2.9 (by no means is it bad for BM, but WSR is just better).