RE: IBO speeds @ less than 70lbs for Bowtech Pro40???
I have a 60#er. BC is 318 at 61#, 29". I haven't shot through a chrono but, a Techno Hunt showed 293-295 at 20 yds. This was with a 320 gr arrow. I'd guess that to be close to 310. Given your draw length, I'd guess you'll be close to the same speed.