I recently bought my girlfriend carbon arrows for her 45 pound draw weight high country bow. When I asked the guy who runs the archery store about broadheads he said that her bow wont let the mechanicals open apon impact at only 45 pounds. Then i wondered... well my bow is only set at 57 pounds, is it still alright to shoot grim reaper mechanical broadheads i got for deer hunting? and i shot a ground hog with them and it looked liked it opened the whole way. so i need some expert advice. What are the pound limits for shooting mechanicals and all that kind of stuff. Thanks.

It's not really the poundage of the bow but the kinetic energy. If you do a searh this info has been posted before along with the equation for finding KE.


http://domino.htcomp.net/ragsdale.nsf?OpenDatabase&Start=1&Count=30 &Expand=8

any good mechanical head will open with just about any impact but its the penitration that will be affected. most people try mechanicals with huge cuts, opening the head takes some minimal energy but pushing 3times more blade through takes way more. i shot mechnicals at 50lbs when i was younger no problems with kills but i used wolverines and steelhead which have normal size cuts of 1 1/8 to 1 1/4"

This is more complicated than it seems. Not all mechanical heads are the same. You have to take into account cutting diamter/cutting surface, the bows KE, how the heads deploys and the type of game your after. At first glance with your set up as well as yourgirls is that you should pick a medium sized fixed blade head or one of the smaller faster opening mechanical heads. My website has some good info if you take the time to read through.
www.broadheadtests.com

5shot -- nice webiste! Thanks for the reference site!