Matching Bows to Arrows

©Dean Torges/The Bowyer's Edge™

The importance of matching arrows to bows has so focused some of us that when sorting arrows into spine and weight groups we go well beyond our skill as archers to perceive differences and perhaps even beyond our equipment’s ability to appreciate our efforts. I don't dispute the importance of arrow spine. But we may be better served by first selecting our arrows to our purpose and then finding or making bows to match them.

The shortage of Port Orford cedar shafting proved a blessing to our generation of hunting archers. In the hurried search for substitute arrow wood, we looked beyond conifers such as pine, fir and spruce to hardwoods like birch, hickory and ash, and in the process came face to face with a generation of archers that valued heavy arrows—the generation roughly forming the first twent-five years of this century, the grandfather generation of our archery heritage.

We are pretty much "fathered" by the archers of this century's second quarter, by archers from the thirties, forties and fifties. This generation set our current preferences and standards with modern bow-making techniques, materials and arrows. Its pantheon of archery greats, including Robert Elmer, Paul Klopsteg, C. N. Hickman and Forrest Nagler, to name a few of the more prominent ambassadors and writers, explored our sport in exhaustive detail, advancing theory and formulae, exploring arrow design and fletching profile, experimenting with backings and laminations, and investigating the nuances of bow tiller—primarily with a scientific eye to maximize field archery performance. We cannot underestimate their contributions nor their dedication to our sport. Our own personal libraries contain large holes without their works.

Because their emphasis lay with field archery, their preferences ran to lightweight tackle that eased the physical demands required of protracted shooting at the butts. Draw weights decreased even further during this period as the development of more efficient target bows provided increased cast, thereby permitting lighter bows without sacrificing performance. Interestingly, these events were paralleled by tackle manufacturers who, through the sale of light equipment, began wooing gun hunters to participate in archery seasons. These part-time archers further increased the demand for lightweight bows.

Port Orford cedar rose up to answer the call as the perfect arrow wood. It satisfied the requirement for a high modulus of elasticity while remaining correspondingly light in weight. We are all familiar with its romance. By the time I came to archery in the mid-50's, 40 to 45 pounds was the norm for hunting weight bows, and 35 pound bows abounded. Cedar arrow shafting was the only arrow shafting.

As an interesting historical side bar, Drs. Hickman and Nagler and Mr. Klopsteg donated all profits from their influential scientific treatise Archery, The Technical Side, including even those of the publisher, "to the National Archery Association of the United States and the National Field Archery Association for the promotion and benefit of the sport of archery." Such was their devotion to our sport and to field archery. Moreover, they dedicated their compilation of essays to Will and Maurice Thompson and Saxton Pope and Arthur Young, men who carried 60 to 90 lb. hunting bows and preferred heavy arrow shafts of hickory and birch, respectively. A dedication reflecting reverence and respect for the past, to be sure, but containing at least some small measure of irony. Such is the turning of the world.

Give and Take

One reason that I wrote Hunting the Osage Bow: A Chronicle of Craft, was to offer a classic short flatbow with a radiused belly as a hunting weapon. I hoped to provide a self bow alternative to a popular style of flatbow currently championed for a design calculated to fend off string follow and thereby store more energy. Of a wide, rectangular cross section and flat across the belly, these self bows directly descended from bows made according to the theories of Dr. Hickman, et. al., bows designed for target archery to provide optimal efficiency.

As a general principle, the less string follow, the more stored energy within the limbs and the better the bow’s cast. Because all woods are stronger in tension than compression, self wood bowyers, especially those who use white woods, tend to make their limbs wide and their bellies flat to circumvent the string follow that occurs when belly wood approaches its elastic limits and takes a set (which happens sooner with white woods than with osage and yew). In the case of the high-stacked limb of the classic English longbow, for example, the neutral plane's closer proximity to the tensioned back forces an unusual amount of work upon the vulnerable belly and therefore requires exceptional length of limb to keep it from failing. In contrast, the flatbow limb that is rectangular or elliptical in cross section places the neutral axis equidistant between back and belly, thereby relieving some stress on the belly by forcing an equitable sharing of the workload. This in turn permits the making of shorter working limbs while decreasing the likelihood of string follow. For understandings such as these, and for their implications, we owe a great debt to these men, our archery fathers.

We cannot ignore their contributions and expect to build efficient self bows. However, in the historical procession of bows and arrows, target bows are so much the junior of hunting bows that the varnish has barely dried upon them. We cannot ignore the accumulated weight of our ancestors' investigations and discoveries either, especially given the important differences between what counts for an efficient target bow on the one hand and an effective close-quarter hunting bow on the other hand.

But the powerful, simple truth of bows is that after enough shots, what works, works, and what doesn't, doesn't, theories, beliefs, prejudices, preferences and even prayers notwithstanding. Consider the following observations: The American Woodland Indian flatbow contained an implicit understanding of the neutral axis and its implications. The radiused flatbow belly that forms in cross section a nearly elliptical bow limb also shares workload evenly between belly and back. Trial and error presumably led to the creation of the Holmegaard bow thousands of years before modern physics validated its ingenuity with graphs and formulae.

Chapter Seven of Hunting the Osage Bow, A Chronicle of Craft, catalogues compelling reasons why short osage hunting bows are better made with radiused bellies and a shortened lower limb. No need to repeat them here. What they all settle out to is valuing a durable and maneuverable bow, quick to point of aim, quiet and stable, one that will minimize the mistakes of an archer loosing one important arrow in awkward situations under less than ideal conditions. The target bow needs to prioritize none of these requirements, and hence grows in directions that satisfy its particular needs.

Self bows, be they long or short, wide or narrow, flat-bellied or radiused, can never approach the efficiency of reflexed laminates or composites, especially those with bamboo, horn, baleen or even fiberglass bellies, because wood under compression cannot handle the work load of these other materials. Self bows therefore almost always require an even distribution of stress throughout their length of limb, sometimes even into their handles, to keep from failing. Not coincidentally, self wood bowyers speak of tillering a bow so that it "comes round to arc" because they are everywhere along the limb flirting with the elastic limits of belly wood.

No straight-limbed self bow (or, for that matter, no fiberglassed bow of this same profile) can approach the efficiency of modern reflex/deflex limb designs that work a smaller section of limb mass to achieve a corresponding draw length and draw weight. However, an advantage to the classic flatbow in this matter is that built short, it will become more efficient than a long, wide-limbed self bow of the same profile and draw weight because of its reduction in virtual mass. It becomes even more efficient when also built as narrow-limbed as the wood will allow.

Whether it withstands the stress, takes a permanent set, or breaks depends upon the species of bow wood as well as its selection, preparation and drying, and greatly upon the bowyer's skill and tillering. However, the successful bow that works its full length of limb will always deliver a bit of handshock because of its inherent inefficiency. And though the severity of that hand shock can be minimized through skillful tillering, a certain amount is inescapable, built in because of the limb mass used to deliver the arrow.

Again, this reality can be mitigated. Significant relief can be found through arrow selection so that the shock becomes a friendly and familiar bump within a firm hand grip. Moreover, arrows that weigh enough to absorb this energy also work to quiet the bow. As with the shortened flatbow, both of these implications favor the hunting archer.

A popular misconception is that increasing draw weights will flatten trajectories, offering compensation for the inherent shortcomings of self bows. Though there is some truth here, heavy bows are better for the hunter because they cast heavy arrows faster and farther than lighter bows of the same design can, not because they cast light arrows better. And the advantages to heavy arrows are far greater than making the bow damp in the hand and quiet off the string.

Fred, and Howard, Too

In 1943, in an article entitled "Hunting Arrows" published in Ye Sylvan Archer, Fred Bear noted that "the growing popularity of field archery" has "created a demand for light weight, fast arrows." He warned against assuming "that the same qualifications are proper for hunting."

Mr. Bear conducted experiments through a shooting machine with six variously weighted arrows (300-800 grains), each in turn shot through six variously weighted bows (45-68 lbs) to prove his thesis that we should shoot heavy arrows (approximately 10 grains per pound of bow weight) through heavy bows (no less than 60 pounds at full draw for an animal the size of deer). The bows ran a sampling of limb design and materials, some backed, some not, some recurved, some straight, of hickory, yew and osage in various combinations and lengths.

The importance of arrow weight and its impact upon penetration stemmed from his observation that complete pass-through penetration of mortal arrows usually killed humanely and quickly, often near the archer, whereas mortal arrows that stayed within game often caused frightened flight, poor blood trails and, occasionally, even lost game, even when the broadhead exited the opposite side.

Using both a shooting machine and an impact measuring device (a bob, suspended pendulum fashion, that recorded the impact of each arrow with a stylus), Mr. Bear found that on the average "the 400 grain arrow struck 20 per cent harder than the 300 grain, the 500 45 percent, the 600 66 per cent, the 700 82 percent, the 800 100 percent."

He noted also that a 500 grain arrow shot from a 61 pound bow struck with a force within 1 per cent of a 600 grain arrow shot from a 45 pound bow. From the other direction, a 68 pound bow with a 500 grain arrow struck less than 3 percent harder than a 52 pound bow with a 600 grain arrow.

Just as some bows are more stable and forgiving than others, and therefore preferable as hunting weapons, Mr. Bear observed that heavy arrows provide the hunter a margin for error by minimizing mistakes of form likely experienced in less than ideal hunting situations. He observed that heavy arrows, averaging ten grains per pound of draw weight, were "less sensitive to correct loose and form" than lighter arrows, which he labeled comparatively "inaccurate" and "unstable" under hunting conditions.

The implications of all this to the hunting archer? In Hunting the Hard Way, Howard Hill maintained that “all else being equal, penetration is the name of the game.” To my mind and preference, this translates to sturdy two blade broadheads at the end of heavy arrows that don't deflect easily from course, shot from quiet, sympathetic bows with the objective being complete pass-through penetration of vital areas on big game animals. If we don’t always achieve this objective, it should still shape our equipment choices, as well as determine our shot selection, because our quarry’s death is not our only goal.

More Bows

We have available to us today a vast array of arrow shafting to choose from, and a vast array of bows to match up with them. We've done nothing more here than reconsider the importance of arrow weight and generalize upon limb design. But we can leave with enough information to map strategies based upon individual preference and purpose. With his own circumstance in mind, an archer can search out the arrow to his needs and then purchase or make the bow styled to maximize that arrow's performance under the conditions of its use, and thereafter tune the arrow to the bow.

Hunting archers must guard against the current trend toward lighter bows without making compensatory changes in arrow weight. Recreational target archers should not feel underpowered pulling light bows, fearful for lost cast, because limb profiles, possible through the lamination of diverse materials, have brought us exceedingly efficient bows to couple with light arrows. And those who wish a multi-purpose bow and arrow combination can find a market place willing and able to meet their needs.

Beyond these observations, we now have convincing arguments to carry to skeptical spouses regarding the practical necessity for owning many bows. After all, how else to acknowledge the diverse kinds of arrow shafting tailored to the various shapes of archery except by matching them up with suitable examples of the bowyer’s craft?