I have a horton supermax 175 which is pretty similar to your legend and you should never shoot anything with a total arrow weight less that 400 grains! You should also never shoot a broadhead with a total wight more than 25% of you total arrow weight. Alot of guys put heavy heads on light arrows but it can will throw off your FOC balance. Alot of guys don't know about FOC and do not realize how it can and does affect you bows accuracy. But all this gets back to your wieght question, I have always used 100 grain heads, thats what shoots the best on a horton arrow that is around 432 or 458 depending if you are shooting carbons or alluminums. If you want to go with a 125 then you need to get a heavyier arrow or you will throw off your FOC. 100 is all you need and will do you fine! Here is a print from easton about FOC hope it helps!



Edit: Just noticed I cut the bottom off, sorry, should be usable now.