Tuesday, June 15, 2010
One of the age-old debates that seems to kick up every now and then when I work on equipment for folks centers around what makes a better hunting arrow - a super fast lightweight arrow, or a slower, heavier projectile. For my part, statistics show that the vast majority of Midwest whitetails, my chief fall target, are bow-killed from inside 30 yards. Range estimation isn't extremely critical or difficult at those sub-30 distances, so in my mind, blazing arrow speeds aren't needed. I'd much rather shoot a mid-weight or heavy shaft at slower speeds, which translates to better transfer of kinetic energy when the broadhead meets the deer. The deadliest rig I probably ever shot was a 29 inch 2317 aluminum arrow tipped with a 150 grain Snuffer cut-on-contact broadhead. That thing would shoot through a 55 gallon drum. Slow, but MEAN!
Here's the simple formula for measuring kinetic energy:
Another often overlooked part of successful bow/arrow set-up is the flight of broadhead tipped arrows. Broadheads must be spin-tested to the arrow, insuring that the arrow spins perfectly true with the broadhead installed. If it doesn't, adjustments need to be made to correct the causitive factor (untrue insert face, one slightly longer blade in a replacement-blade broadhead, simple debris on the broadhead ferrule). I make sure every broadhead arrow I put in my quiver spins on my caloused palm without any wobble of any kind. I prefer feeling the spin to looking at it in a tester.
And given real-world conditions of poor releases, wind, flinches, twigs/grass in the arrow's path, etc, an arrow that is forward-weighted will perform much better than one that is balanced near its center. In other words, the arrow should have a front of center balance of no less than about 8%, and somewhere in the 10 - 12% range is generally better (providing the arrow has sufficient spine to accomodate it). The transition to 100 and 85 grain broadheads has created some FOC issues, since lighter tips reduce FOC, all things being equal. But the advent of small, Blazer-type vanes has somewhat reversed this trend. At any rate, anyone putting a bow hunting arrow together should take FOC balance into consideration.
Here's the simple formula for measuring FOC:
I once had a medical doctor friend that spent nearly $1000 on a new bow, rest, sights and so on. But when bow season rolled around, he had 3 different shaft types in his quiver, with 2 different broadhead designs (some 125 grain and the others 100 grains) adorning them. And nothing was overly straight or sharp. I was dumbfounded, and spent 30 minutes lecturing him and another hour or setting up 4 matching hunting arrow. If you're serious about shooting animals with a bow, pay attention to more than just your bow. The arrows and broadheads are the only part that hit the animal, so no matter how pretty/fast/expensive your bow is, performance is measured at the broadhead end of your shot.
Posted by Decoy Guy at 11:31 AM