Jeff Im not sure what's going then...last year my bow was set up at 74# with a 90 gr muzzy and an arrow weight of 309 gr!! like I said, I got 8 out of 9 pass thrus[&:]I did not know my arrow was that light, or else I would have shot a much heavier arrow....only thing I can think to try is up the # ?? have you killed a deer with the new arrow set up??