My son has been practicing with 85gr field tips and when we went to get broadheads all we could find was 100gr. How much difference in trajectory at 15-20yds? Thanks in advance for your comments.
Stepchild

Without knowing the weight of the bow it would be very hard to say. On average I figure at 15 to 20 yards most set ups would see very little.
The real problem would be how well the arrow flew due to the change in spine. The heavier head will cause the shaft to flex more and if you were on the "light" side with your shafts you may have real problems!
Good luck!

Bo-n-aro,
Thanks for your reply. We wound up buying some 85gr. Thunderheads as the 100's just didn't fly right. The Thunderheads cured the problem.
Stepchild