I can't remember the numbers but when I bought my carbon sst arrows I did all the figuring. Just to make sure, what do you go by when looking for broadheads in terms of weight. I think I am shooting 100s but was thinking about dropping down to 85s. I am pulling back 70lbs, my shaft length is 29.5, my arrow weight per inch is 10.5, I can't remember the shaft size, they are 240s but I dont' think that tells the shaft size. The arros size is correct, I am just worried about dropping the bh weight.