Took a few shots with some under spined arrows that I have sitting around and arrow flight was superb. I'm shooting a tad over 70 lbs with a 29 inch draw and 30 inch arrows and the spine was only 4.24 instead of the 3.20 - 3.70 that most charts call for. I think they even flew better with 125 grain tips than 100 grains. I haven't tuned the bow yet as I just broke in new strings but the 4.24 spine arrows were much straighter flying than the 3.60 spine arrows that I had been using with that bow. Has anyone shot that little of spine and that much poundage with any success?