It’s no secret that Eastman Outdoors produces some of the best archery ammo available, so last year we took an in-depth look at their entire Carbon Express arrow lineup to get a better understanding of just how the company’s exclusive arrow technologies work. This year we took it a step further, examining the 2012 offerings and tapping into the manufacturing insights of Carbon Express’s own arrow-making guru, Lennie Rezmer.
Without question, today’s arrow consumers are better educated – both target archers and bowhunters – and they have a better understanding not only of the sometimes subtle differences between various arrow models but also of the necessity to match those arrows properly to their particular bow setups. Additionally, archers are looking for precisely matched arrows within any given batch. But while today’s archers may be better students when it comes to the science of arrow selection, our ever-evolving archery tackle seems to always introduce new factors, some of which border on the mysterious.
For instance, the term “dynamic spine” has only recently crept into the lexicon of bowhunting. When the topic of arrow “spine” comes up, most bowhunters think of “static spine,” which is the stiffness of an arrow measured at rest, and they figure that’s all they need to take into account in order to select the perfect hunting arrow. Now there’s dynamic spine, which refers to what happens to an arrow’s spine immediately upon release and during its flight. If you’re wondering why it’s important, take a look at your new compound bow. Does it look, feel, or shoot differently from the bow you shot 10 years ago? Quite possibly it does. That’s because of technological advances in cam, limb, and overall bow design. If you’re scratching your head wondering just what this has to do with arrow choice, consider what Carbon Express’ Lennie Rezmer has to say on the topic:
“Many of today’s bows are built for speed, which means they have a long power stroke. These bows, in simple terms, are designed to deliver a different type of dynamic stress to the arrow as opposed to older, slower bows. To understand this, consider how a modern bow rolls over and feels when you’re at full draw. That creep in your shoulder, if you should let down even a little bit, is evidence of an aggressive power curve. These bows harness a lot of energy and are very quick to impart that thrust on the arrow as soon as you trigger your release.”
It’s not just the immediate release of energy on the arrow that necessitates paying attention to dynamic spine, it’s the length of the power stroke as well. Lennie Rezmer explains, “Ten years ago bows were only thrusting arrows for 12 or maybe 14 inches. Today’s bows provide energy right away and result in a thrust that lasts more like 17 to 20 inches. This means that a static spine of .400 just changed to .500, and [the more weakly spined arrow] is inadequate. Modern bow designs have increased the divide between static spine and dynamic spine to the point where we notice it now, and if you’re under-spined due to this division, your accuracy will suffer immediately. This is also largely the culprit when speed bows are considered to be “hard to tune.” They actually tune just fine when firing correctly-spined arrows.”
If you’re in the market for new arrows, or you’re freaking out because you think you might be sending improperly spined arrows down range, go to http://carbonexpressarrows.com/shaft-selector. You’ll appreciate their comprehensive chart. It takes into account starting draw weight, tip weight, cam design, arrow length and a litany of other factors before determining your “calculated draw weight.” Once calculated draw weight is determined, it’s time to move on to the next step, which highlights the varying arrow models offered by Carbon Express. According to the folks at Eastman, this is the very best way to determine which CX arrows you should be shooting.
It’s also important to note that Carbon Express’s exclusive arrow technologies like Dual Spine Weight Forward, which is found on their extremely popular Maxima Hunter and Maxima Hunter KV arrows, work in your favor where dynamic spine is concerned. In fact, once you’ve run your information through the shaft selector and discovered the correct arrows for your setup, technologies like Dual Spine Weight Forward should put your mind at ease and increase your accuracy. Carbon Express certainly didn’t invent dynamic spine, but they’ve figured out how to deal with it, and they’ll make sure your arrows are spined perfectly for your bow setup.
The arrow experts and CX didn’t invent the arrow nock either, but their latest generation of nocks is a far cry from anything the market has ever seen. Their new CX Precision Nock looks like a traditional nock, but just as in addressing dynamic spine issues, it’s what you can’t see that often makes the difference in accuracy.
“For 2012, we took our nock design to a much higher level,” Lennie Rezmer began. “To start with, we looked at how a nock fits on the bowstring. What we learned is that the right fit in the throat of the nock as it’s snapped to the string, along with where the nock actually fits the string once it’s seated, are extremely important. We ended up with nocks that are not too tight when they snap on and that can slide up and down the string with little effort. That’s truly the sweet spot for nock-fit.”
“The second thing we looked at is the density of the nock. Previously we’d found that overall nock density could vary greatly, which resulted in nocks that exhibited different amounts of pressure on the string. So, we set out to develop much more consistent material density,” Rezmer explained. Through trial-and-error with varying molds, the engineers behind the CX Precision Nock hit on a method for injecting from the top, instead of the traditional method of injection from the side. The result is an extremely consistent straightness and overall density.
Certainly, manufacturing consistency and the resulting more consistent nock performance will get you better arrow flight, but the tightness of your arrow groups boils down to something Lennie Rezmer called “four-axis straightness.” Lennie explained, “If you snap a nock into the shaft and turn it 90 degrees, it should be dead center. If the nock is off axis, it will wobble. This is often to blame when you think you’re dealing with out-of-straightness arrows. If your nocks are off by .003” or .004” to one side, it is worse than having an arrow shaft that is .009” out of straightness, because essentially you have a launching pad that’s out of kilter.
If you’re wondering if your new Carbon Express arrows are fitted with CX Precision Nocks, it’s likely that they are. All of their standard hunting arrows have been outfitted with these nocks since August 2011, and one of those offerings, The Crush, is creating quite a buzz.
The Crush arrows were designed to address the needs of those archers looking for an arrow that delivers flatter trajectory, consistent accuracy, and enough kinetic energy for whitetails and larger big game animals. Two spine options are available, with weights of either 8.7 gpi or 9.5 gpi. Outfitted with Raptor Vanes, The Crush arrow is covered in the unique Diamond-Coat finish, which cuts down on the noise caused when you draw your arrow across the rest. To ensure consistency, each batch of The Crush arrows offers a straightness tolerance of +/- .003” and a weight tolerance of +/- 1.0 grain.
Of course, Carbon Express has added plenty of innovative products to their 2012 line, all of which can be found at www.carbonexpressarrows.com. If you’re interested in refilling your quiver for the upcoming bow season, or simply want to figure out if you’re shooting properly-spined arrows, their site is worth a visit. Also, if you’ve splurged on a new bow, something that’s designed to deliver arrows downrange at blistering speeds, you might want to think about dynamic spine when it comes to arrow selection. What you find just might eliminate a lot of time spent wondering why your new rig seems to be so tough to tune.
Once again, Carbon Express has laid claim to a leadership role in arrow technology. And I concede, it seems to suit them just fine. In fact, it’s likely they’ll assume the role for many more years. What’s better, it’s likely they’ll deserve the role for just as long.
The more aggressive, increased power stroke and overall heightened mechanical efficiency of today’s modern compound bows affect your arrow’s dynamic spine more than bows from just five years ago. This increased stress on your arrow does complicate shaft selection, but you’ll find the perfect match at http://carbonexpressarrows.com/shaft-selector.