There is a problem with your numbers.You don't hardly EVER get an increase in ke when going lighter.



Usually there is another problem,like underspined arrows not being as efficient and/ or tune causing a problem..Didn't you have problems with this?



friction is idependant of speed once an odject is moving,faster DOES NOT mean more friction.

http://hypertextbook.com/physics/mechanics/friction/ you have to go way down to the bottom right before problems to read this statement.


I actually have a Machinist Handbook that staes that friction decreases as speed increases.Laws of dry friction.



But I would choose the heavier if I could get that kind of speed from a 425 grain arrow,hell,I don't get that from a 365 gr arrow.