just happened to save this....was going through some stuff today thought ya might like it. Was from Bills webpage. dont thing the pic will work but here's the rest of it.
Valerie's Quiver
Barrel-taper Hollowtail Arrows
Barrel-taper Hollowtail Arrows are the most perfectly dynamically balanced wood arrows available today. If you follow our point, spine, and tuning directions, we will guarantee them to be the most accurate wood arrows you have ever shot.
The following are the special features of the Matlock Barrel-taperHollowtail arrows:
1. Spine +/- 2.5 #, Weight +/- 5 grains.
2. Straightness: These arrows are straightened with a straightener we designed to produce the straightest wood arrow available.
3. These arrows are Barrel-tapered on a machine that we designed and built over a four year period to produce a dowel 0.343 at the ends and 0.360 in the center. This machine holds roundness tolerances of +/- 0.0025".Barrel-tapered arrows have a much higher spine to weight ratio than parallels or tapered shafts.
4. Hollowtailing is accomplished by a deep hole drilling setup that utilizes a rifle barrel drill and rotates the shaft at 3600 rpm. We drill a hole 1/3 the diameter of the shaft 4 1/2" deep in the rear of the shaft. This removes 18 to 22 grains of weight off the back of the shaft which gives the feathers less mass to move back into line after the arrow leaves the bow. Tapering only removes an average of 11 grains and weakens the shaft substantially (about 5#). Drilling only drops the strength 2/10 of 1%.
5. Matlock Arrows are dipped with four coats of nitrocellulose lacquer with a white crown dip. This procedure leaves a finish that is almost as smooth as glass and does NOT stick and heat weld to excelsior bales or other targets. An occasional application of WD40 will make them pull really easily.
6. Matlock Arrows are crested with bright acrylic enamel paints. Two colors are standard, extra colors are $5.00 each.
7. We prefer Douglas Fir; however, we can custom dowel woods such as Purple Heart, Ebony, Wenge and other exotics where VERY heavy weights are required for African game, etc. Port Orford Cedar is also available. Prices on custom doweling for special purposes are dependent upon wood prices at the time the job is done.
Prices:
Full-length Arrows $94.00 per dozen
Cut to Length and Pointed $97.00 per dozen
Packaging and Shipping $5.00 (Priority Mail w/ $100.00 insurance)
Hollowtail Arrows Fact Sheet
Hollow arrows are nothing new. The Native Americans were using cane and reeds for shafts thousands of years ago.
In R.P. Elmer's book Target Archery (1946), he lists several instances of experimentation with tubular arrows- one as early as the 1911 NFAA Nationals. Any serious target shooter can tell you that the most important single facet of good arrow flight is balance point or fore-aft weight distribution.
Obviously, it also is important in a hunting situation. Flying a broadhead is much more difficult. If you look at the major difference between aluminum arrows and woods it is not strictly straightness that make the difference in shootability but weight distribution! Even the smallest alloy shaft has not only the point weight 125 or 145 grains. But the weight of the insert (approximately 55 grains) for a total of 180 grains up front. To equal that weight distribution on a wood you would have to use a 190 grain point on an arrows with a total weight of 600 grains or more.
The lighter shafts do not show the problem nearly as much but it still exists. Thus the need for huge feathers on woods to straighten them out quickly. Footed shafts also help some as they are heavier on the front. Tapered arrows are another way to correct weight distribution, but tapering also affects spine! Tapering can only take off about 8 to 10 grains of weight in the rear.
The answer? Hollowtail Shafts! By drilling a 3/16" hole 4.5" deep in the back of the shaft you can get 18 to 22 grains weight reduction in the rear. This helps tremendously. According to experiments done in the Longbow Magazine, tube tailed arrows made by David Ellenbogen of Rivendell Archery, Harwinton, CT straightened out 36% faster than tapered wood arrows.
As shafts were not available at that time, I undertook my own experiments and designed and built the machinery to do straight, true, drilling in wood dowels. I offer this service in minimum lots of 100 including cutting on absolutely true nock tapers at the same time for the price of $1.00 per shaft. This also includes straightening each and every shaft before drilling.
If you want your shafts weight and spine matched is an extra $0.50 per shaft. Some customers have expressed concern about the possibility of breakage of these types of arrows. I have experimented extensively with these shafts for years and have trashed over 100 of them shooting into rocks, trees, etc. and have had only one break at the end of the hole! (It was a glancing blow on a tree limb.)
According to Machinery's Handbook, pg. 462, (table giving comparative torsion strength and weight of hollow and solid shafting with same outside diameter) a piece of material with a hole 1/3 of its diameter in the center suffers a 1.24% loss of strength for an 11.11% loss of weight. While I was unable to find reference material on the exact loss of column strength, my experiments with a spine tester and dial indicator show no loss of spine from the drilling of the hole.
I also fired many arrows down range from my longbows that average 208 to 215 FPS with no adverse results. In testing these arrows with a compound with sights, I have concluded that the groups I shoot are 1/3 the size of my groups with undrilled arrows of the same spine. Try them. You will be pleasantly surprised!
Topic: Matlock Hollow tail tapered arrows (Read 551 times)
