Tuesday, June 15, 2010


In the colder months my basement is a makeshift taxidermy shop where I put together full mount turkey deeks.  But when it's warm out, I'd rather be outside shooting my bow.  It's then that my basement gets reogranized into an archery shop.  This past weekend I put my nephew's bow back together after his string mysteriously came off (dry fire maybe?).  I then found a broken serving that needed fixed, adjusted a small cam timing issue, waxed string and cables, and installed new string silencers.  After about an hour of fiddling around, Brandon was back on the range stacking arrows.  I love this stuff!

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.

Wednesday, June 9, 2010


I like to tinker with archery equipment.  I got my first bow before I turned 10 - a Bear Blue Denim compound (I still have it).  I still remember my dad and brother trying to change the draw length for me out in the front yard.  Dad forced the limbs together while Ricky moved the cable ends to holes drilled in the eccentric brackets bolted to the ends of the limbs.  It came from Target in South Bend.  I shot it so much that dad realized I was serious. 

When it became obvious that I'd outgrown the Blue Denim, dad consulted with a cousin, Billy Joe Risner, who had his own basement pro shop, and was notorious for trying out the latest-and-greatest bow gear.  He directed dad in purchasing my first REAL bow, a Martin Cougar Magnum.  That Martin still ranks as one of the top 5 gifts of my life, and I still have it.  The craftmanship is exquisite, and every year I toy with the idea of setting it up and killing another deer with it.

Anyway, I've been hooked on archery since I was a little boy, and my affliction doesn't seem to improve.  I recently bought a new bow press that handles the modern parallel limb bows, and this week built a prototype draw board to help look at cam timing, cam lean issues, nock travel, draw force curve dynamics, and much more.  I'll eventually have my brother help me build a metal (welded) frame instead of the wood variety I'm experimenting with, but the fun is in refinement!

As an example, I put my Hoyt ProTec on the draw board last night, and used the draw lenght/weight data to build this draw force curve table:

It shows the bow has a pretty gradual build to peak, a wide peak top, and a fairly gradual shift down to the wall.  This curve doesn't show it, but the bow has a very narrow valley at full draw.  Taking peak draw weight (44 pounds) and subtracting holding weight (16 pounds) gives the let-off amount of 28 pounds.  Dividing 28 by 44 and multiplying by 100 gives the percent let-off of 63.6%.

I'll compare these numbers with those of my new Maxxis when I get a chance.  Note that I've shortened the ProTec up as much as the cam modules and cable/string twisting will allow, and backed the limb bolts out as far as possible.  I'm setting the bow up for a beginning adult archer that needs low draw length and weight.