For the flight shoots, there is a minimum arrow mass of 500 grains in the primitive divisions. These records are being set near the Bonneville Salt Flats which is just under a mile above sea level. I think that the air is about 20% thinner than at sea level, so this makes a difference with high-drag broad head classes. That doesn't mean the arrows go 20% farther but it does make a difference. The broadhead event is also different than regular flight classes because a longer draw can be an advantage. Finally, the records are set with all-natural string materials, but I don't see this as much of a disadvantage anymore as we keep learning more about the potential of natural fiber strings. In fact, a good properly made linen string will blow away a B50 string for performance. Finally, there is a little luck that can play a role in the records set. It is great if you have a light and steady tail wind, but it can be a mess if the winds are constantly shifting and turbulent.
Here are a few primitive class results from the 2010 Broadhead Flight Nationals held this past August:
Unlimited Complex Composite (Horn bow in this case) - 237 yards, 1 ft by Bede Dwyer for a new World Record in this class.
50-lb Complex Composite - 205 yards 2 ft by Jaap Koppledrayer
Jaap kindly let me shoot his horn bow in this same class in another round and I managed a distance of 204 yards.
Unlimited Simple Composite (2-lam or backed bows) - 220 yards (an old Marc St. Louis Bow) shot by James Sanchez that may have had a draw weight in the upper 50's with the length arrows he shot.
This was the first time I tried the broadhead class and it is a lot of fun. The arrows are moving relatively slow and it is fun to watch them sail across the sky. I'd recommend it if you get the chance! A little work on the arrows and you might find yourself in the record books with a design like you posted here.
-Alan
