What You Need to Know About Crossbow Bolts
With the use of crossbows as a hunting weapon gaining popularity rapidly across much of the country, beginning crossbow hunters are seeking out what to look for when purchasing crossbow bolts. Sure, it is important to research the actual model and brand of crossbow like any other piece of hunting equipment before making a purchase, however, what many hunters and shooters are missing is what bolt is best for their crossbow setup and for the species of animal they intend to shoot. Deciding on which crossbow bolt to shoot, what the best crossbow bolt is for you, or building crossbow bolts specifically for a hunt is information that any crossbow hunter should know.
Looking for a Reliable Crossbow Bolt
A lot of variables make up a good crossbow bolt. Until you know which bolt performs the best from your crossbow it is not as simple as walking into your pro shop and purchasing a six-pack of bolts and hoping for the best. Crossbow bolt length, the weight of the entire bolt, type of nock, and shaft material should all be considered before making an initial purchase. Crossbow manufacturers have recommendations for which type of bolt shoots best and these recommendations should be followed. They will also provide the necessary information for the weight, length, and nock type for their crossbow. However, when it comes down to it, it’s obviously up to each individual hunter to choose the best crossbow bolt for their crossbow using the guidelines set by the crossbow manufacturer. If you do not shoot the correct bolt or nock, you run the risk of damaging the crossbow and/or yourself.
KILLERTECH™ PRO 20” CROSSBOLTS
Killer Carbon Meets lighted performance – our KillerTech™PRO bolt now comes pre-installed with industry-leading NockOut™ lighted crossbow nocks. Killer Instinct® Lumix Lighted Nocks stand up to repeated use put of high-powered, high-performance crossbows – proven dependable after hundreds of shots! We are confident these bolts will exceed your expectations and improve your confidence in the field.
Crossbow Bolt Construction
Crossbow bolts are similar to construction to that of arrows shot from compound bows. But, with many crossbows shooting more than 400 fps, the bolts need to be tough enough to prevent them from exploding when shot.
Bolts range in length from 16” to 22”. The most common length is 20-inches. It is possible to get away with a longer bolt than recommended, but anything shorter than what is recommended could cause the broadhead or field point to get caught on the crossbow rail when fired. However, it’s hard to think of one good reason why you would shoot a bolt longer than the manufacturer’s recommendations.
The total weight of the bolt includes the weight of the bolt, crossbow nock, insert, vanes, and broadhead or field point. Just about all bolt manufacturers will list how many grains each shaft weighs or how many grains are in each inch of the shaft. For example, your bolt might say 15 grains per inch (GPI). If your bolt is 20-inches, multiply 15 x 20 to figure your bolts weight. In this example it is 300 grains. Now all you have to do is add the weight of the nock, insert, vanes and tip for a total weight. A heavier bolt, at least 400 grains not including the head, will have better downrange energy and offer better penetration. Keep in mind that even though a bolt will leave the rail quickly, a heavier bolt will quickly lose power as it flies. A bolt on the lighter end of the manufacturer’s recommendations will fly faster and will give the shooter an extended range but might not get the desired penetration.
When purchasing a crossbow, the speed ratings are often rated using a 400-grain arrow. The heavier your arrow is, the slower it will fly. For example, if your crossbow is rated at 350 fps, it will only travel at about 315 fps if you are shooting a 500-grain bolt. This matters when thinking about kinetic energy. How fast your bow shoots, the total mass of the bolt, and distance traveled all plays into how much force is delivered upon impact. Keep in mind that the larger your broadhead is, the more kinetic energy is required to get good penetration.
A Bolt’s Kinetic Energy
For small animals like deer and antelope, 23 pounds of energy is the minimum amount of kinetic energy needed. For bigger animals like elk and black bear, the minimum is about 43-pounds and bigger animals like grizzly bears will require 63 pounds of energy. For every 10 yards your bolt travels, you can expect to lose 3 to 4-percent of energy. If you bolt is delivering 80-foot-pounds of force at the initial shot you can expect at 10-yards you will receive 78 to 77-foot-pounds of kinetic energy. At 20-yards those numbers drop to 75 -74-foot-pounds of kinetic energy.
There are several kinetic energy calculators on the internet that will help you figure out how much kinetic energy your bow is delivering. However, you can figure it for yourself. All you need to know is the feet per second (fps) a bolt is flying and the total mass weight of your bolt.
M= total mass of arrow (grains)
V= velocity of arrow (fps)
Bolt Fletching and FOC
As far as vanes go, some people prefer the smaller 2-inch vanes over the larger 4 or 5-inch vanes. The reason some like to shoot the smaller vanes has a lot to do with the arrow front of the center ratio (FOC). The smaller vanes will take away some of the weight off the rear of the bolt. This will add to the FOC. Depending on your overall setup, smaller vanes can help improve accuracy. Once you have decided on length and the total weight of the arrow, practice shooting some bolts with different sizes of vanes to see which one flies better for you.
Nocks come in several styles and shooting the wrong one from your crossbow could result in the string jumping the nock and causing a dry fire. Look to see if your crossbow shoots half moon, flat back, capture, or hybrid moon nocks. From there you will want to find a lighted crossbow nock that is the same type of nock. Because crossbows are delivering bolts as such a high rate of speed, they are often difficult to see upon impact. This often leaves the hunter guessing where the bolt struck the animal. To combat this problem it is a good idea to use a lighted nock. The two styles of lighted crossbow nocks by Nock Out® are half moon and flat back. Always use the nock type your crossbow is designed to shoot. Most crossbows will not shoot both styles of nocks.
Companies are now offering expandable blades designed specifically for crossbows. They are very similar to the same head you would shoot out of your compound. Whether you plan on shooting a fixed blade or an expandable specific for crossbows be sure to sight your crossbow in for the broadhead you intend to shoot. Even if you are shooting the bullseye at 30 yards with your field point that does not mean a bigger broadhead will fly the same. With expendables, you stand a better chance of getting the same grouping you did with your field points.
Building Your Own Bolts
If you plan on building your own bolts, it not very complicated. Just be sure each bolt is constructed using the same components. You do not want different grains of inserts, nocks, etc. If you were to do this, no two bolts would fly the same. Even when everything should be equal you might find that one bolt is a little off.
Every component of the bolt will affect how it flies and even penetrates. It might seem overwhelming to try and figure all this out at first. But, it is really a lot easier than you think. The crossbow manufacturer’s recommendations will give you a jump start. It is then up to you make the necessary little adjustments to get the bolt that flies best for you.