Tim, you know my setup and my feelings on this but for others reading this: My experience is shooting 6 elk that I have killed now with traditional bows-all under 50#. The fastest arrow was going 163 fps. and the slowest was 143 fps. ( 143 fps was this year shooting a 41# recurve and 630 gr. arrows). All arrows were between 590-650 gr. All broadheads penetrated to the other side of the elk, one broke through a leg bone on the off shoulder. One year I shot lighter arrows (about 485 gr. and lost 2 elk that I hit (very poor penetration both times with the same broadhead). My advice: Don't worry about your bow weight (as long as it's legal). Worry about your arrow weight (at least 600 gr. for elk), your broadhead, your accuracy, but not your bow weight. I have notice VERY little difference in penetration when my arrows were going relatively slow or faster. I don't have any experience with anything slower than 143 fps but 630 gr. @ 143 fps. or faster is deadly.