Broadhead Buyer's Guide
Author: Frank Ross
A broadhead is a large cutting point assembly, attached to an arrow shaft for hunting. The proliferation of broadhead designs and blade configurations are diverse, making the decision on which one to use under a given set of hunting factors confusing, but it doesn’t have to be so.
Each year manufacturers come out with new models designed to maximize cutting efficiency, minimize flight deviation and increase impact stability, so even if you're content with the broadheads you've been shooting for a long time, it might be worth considering some of the newer broadheads.
Broadheads can be divided into two categories based on their physical makeup and further depending on the number of blades they sport. The two main categories are fixed blade, and mechanical blades. Within those main categories you will find additional variations or sub-categories. Additionally, various designs bridge the basic model descriptions by adding features like cut-on-contact blades on the tip.
For most bowhunters, broadhead selection is a matter of personal preference based on experience, the speed at which they shoot, and the game being sought. If you're new to bowhunting and short on experience, here are some guidelines.
As a general rule, bowhunters with slower shooting speeds, created by lower draw weights, should use fixed-blade broadheads with smaller diameters of 1-1/4 inch or less to improve penetration. An additional consideration for shooters with slower speeds would be to select a broadhead with less resistance such as a two-blade broadhead with a small ferrule. Lesser resistance will equal deeper penetration.
Shooters with higher draw weights and faster speeds have more options. Increased kinetic energy will give the advantage of using larger diameter fixed-blade broadheads or the newer designs in mechanical heads that provide even greater diameters of cutting surfaces. With sufficient penetration, these larger broadheads have the potential to produce corpulent blood trails, but there is a point of diminishing returns with broadhead size. Although mechanical blades are available up to 2 3/4-inches, 2 inches is the maximum effective size for deer-sized animals. Larger blades should be reserved for smaller game such as turkeys when penetration isn't an issue.
The number of blades that a broadhead has will have a direct impact on the blood trail, with more blades producing the best effect. The theory is that with broadheads using three or more blades, at least two are cutting across the grain of muscle tissue, making it more difficult to avert blood loss by muscle fibers closing up with a cut that happens to run with the grain.
• Fixed-Blade Heads
• Replaceable Blade – The blades are removable for sharpening or replacement, and on some designs the points are replaceable.
• One Piece – Full-blade broadheads have cutting edges that extend from the very tip of the point back to the rear portion of the blade(s). These broadheads are available in two blade two-edge models and four blade four-edge versions.
• Mechanical heads – Have blades that fold into the body to reduce drag and deflection during flight. The cutting blades extend upon penetration and give these heads their name.
Fixed-blade broadheads can be broken down into two categories, 1-piece and those with replaceable blades. Replaceable blade broadheads are very popular because you don’t have to worry with the tedious process of sharpening the blades’ edges. When they lose their edge, due to practice or field use, you simply drop in a new razor-sharp blade.
Within these categories you’ll find two-blade, three-blade and four-blade configurations. For novices, not as experienced in bow tuning, smaller and fewer would be two words to consider strongly when it comes to head selection.
If your bow is poorly tuned, when an arrow leaves the rest, its flight will be affected more readily. An arrow that leaves with its fletching end raised will tend to catch the wind and take a sharp dive in its trajectory. Conversely, when the fletching end drops on release, the lower rear angle will cause the blade to catch the wind and plane upward.
For the same reason, increasing the number and size of multiple bladed broadheads will have an increasing effect the bigger they get. If you want to minimize tuning your bow, stick with smaller broadheads. You’ll still need to do some tweaking, but not as much.
Leading Edges - Chisel Tip vs Cut on Contact
Broadheads that use a chisel tip have to punch or rip through an animal's tough hide before reaching the broadhead's blade surface that does the cutting. This will use some of the arrow's kinetic energy thus impeding some penetration. This style of tip is one of the most durable, and have been known to punch through heavy bone with no damage to the tip.
Cut-on-contact tips don't have to punch through the hide, instead they slice through the hide. This requires very little energy, therefore penetration is not affected as much.
This ingenious innovation has gotten a bad rap, largely because of a limited number of bowhunters with bad experiences, and justifiably in some cases due to poor initial designs. However, mechanical heads have come a long way since they were first introduced.
The truth is that mechanical heads aren't ideal for every application, however, they do meet a need and many dedicated shooters use them successfully every season. Certainly, improvements in original designs have minimized the number of disappointing experiences, but selection for particular applications is also a major factor.
Mechanical heads have one major advantage; they fly very close to field points and require very little tuning to attain tight groups. The critical issue to keep in mind with mechanical heads is that the blades have no support for the trailing edge. Blades that use thicker metal for the extendable blades will withstand greater stress and have less flex upon impact. While some mechanical blades are as thin as .020", Cabela's Lazer Strike Mechanical broadhead blades are made from razor-sharp, heavy-duty stainless steel that is .036" thick. Also, the length of blade you select should be limited when targeting larger species.
While mechanical broadheads are available with blades up to 2-3/4", hunters should limit the size of broadheads to a maximum cutting diameter of 1-1/2" when going after elk or big-bodied animals like moose or bear. Smaller blade diameters will give you greater penetration and improved performance with bigger-boned animals.
That said, there is another factor to consider and that's the force that's driving the business end. Mechanical broadheads up to 2 inches in length are fine for game up to deer-sized animals as long as you have enough kinetic energy to drive them home. Industry experts recommend at least 55 pounds of kinetic energy for the larger heads and 65 pounds of kinetic energy when going after elk and large game. The 65 pounds of kinetic energy translates roughly into the result achieved by launching a 400-500 grain arrow with a 60-65 pound compound bow.
You can use this formula to in order to calculate kinetic energy know exactly what you are producing with your particular set up:
ke=M * v2 / 450,240.
ke=Kinetic Energy, M=mass (weight of arrow in grains), v= velocity of arrow in f.p.s., 450,240 = (gravitational constant of 32.16 * 7000 [grains])
For example: An arrow with a weight of 450 grains, traveling at 265 f.p.s. will have 70.19 pounds of kinetic energy. (450 x 70,225 (265x265) / 450,240 = 70.187).
Here is a tool to help you quickly find the Kinetic Energy of an arrow:
With Mechanical broadheads you still need to tune your bow to achieve maximum performance in both penetration and accuracy. The adjustments required to perfect your setup are less than with traditional broadheads, but even slight variations in flight can rob you of valuable energy. Tuning is time well spent regardless of what you shoot. A good compromise for mechanical broadheads is to shoot the smallest diameter, 1-1/4 inches, so that you get maximum penetration and still have the advantage of the accuracy characteristics of mechanicals.
The next decision after determining which style of head you want is weight. Industry experts recommend 100-grain heads for carbon and lightweight aluminum shafts, and for heavy aluminum shafts, 125-grain heads.
Once you decide on which weight and style of broadhead you want to use, it is incumbent upon you to set up and tune your bow properly. Before you start tuning your bow, make sure your arrows are perfectly straight and that the broadheads are installed properly. You can check head alignment by spinning your arrows to make sure there is no wobble of either head or shaft. Keeping half a dozen arrows set aside strictly for hunting is a good idea, since it eliminates the potential wear from use during practice sessions.
Bow Tuning Tips
1. The first step for two-cam bows is to make sure your wheels are synchronized to roll over at the same time.
2. Check that your arrow rest is aligned for a center shot for a release aid, or outside (slightly away from the bow) for finger shooters.
3. Rotate the nock to eliminate fletching contact or change to a less aggressive helical configuration. Carbon arrow shooters should consider four-inch fletching.
4. For finger shooters, arrow spline is a critical issue, so make sure you have properly matched equipment.
5. Shoot through paper at a range of 10 feet.
6. Move your rest right or left to compensate for tail-right and tail-left flight as indicated by paper tears.
If these steps haven't produced the desired results, release aid shooters should evaluate their nocks. If you are using nocks that are larger in diameter than your shafts, the nock may be hitting the rest and kicking the arrow. Also, the way you grip your bow will have an affect on arrow flight. If you're having problems eliminating tears, this would be a good area to investigate. Open your fingers when releasing to avoid any chance of influencing the arrow's flight by inadvertent pressure. Finally, check your rest for contact to make sure you have adequate fletching clearance. If you can't totally eliminate fletching contact you will need to experiment with different styles of rests.
If none of these tuning tips have resolved your paper tear problems, then you should consider a visit to the experts at one of Cabela's retail stores, or your local pro shop.
To ensure a quick and humane kill, you'll also need to spend some time practicing with your new broadheads. Even the biggest, sharpest of broadheads will not bring an animal down if it's stuck into a non-vital part of the animal's body. That's one of the compelling aspects of bowhunting; going back as far as its creation, its still a stick and string. What you do with it is totally dependent upon the skills and dedication of the person holding and ultimately releasing the string at the right time, putting the arrow in the right place.
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