i bought a dozen new/old Bear cedars with Bear broad heads in the original box once for $12, I figured that I would use the the heads on my wife's arrows and find out what the spine was and use them on any appropriate bow. To my surprise there was no attention paid to the nock/grain alignment and the arrows as fletched showed a wide spine variation. I checked the spine with the proper alignment and found that they ran from 47 to 51 pounds, the box was marked 40 pounds. I stripped them and rebuilt them and gave them to a friend with 6 Bear heads and 6 blunts on them.