Crossbow Arrows and Components
There is a misconception that todays modern crossbows shoot bolts. This couldn’t be farther from the truth. A crossbow bolt is much shorter than a crossbow arrow. Most of the time a bolt will will be 5” in length or less. Crossbow bolts also weigh a good bit more than any arrow you would ever shoot from a crossbow too. Most bolts don’t have any type of flexible fletchings or vanes, but rather very stiff guides or flutes if any at all. Many times they are made from a solid piece of metal or wood. So why do we call crossbow arrows bolts? Well for starters the manufacturers of crossbow arrows refer to them as bolts which technically is incorrect. I think the term crossbow bolt has been around for so long, it has just become socially acceptable to call them bolts. But from this point forward, we will be referring to them as what they truly are, and that is arrows.
There are two main materials a crossbow arrow can be made from. Carbon and aluminum. Each have their own advantages and disadvantages. Either one you decide to use will be more than adequate for any hunting situation. Chances are your crossbow, if bought in a package will include some arrows. Most hunters will end up using the supplied arrows with great success. Then, if you should damage or loose any of those supplied arrows, most hunters just purchase more of the same type of arrow they started with. You should know however that there are much better arrows out there then that which come from the factory. I’m not saying that the supplied arrows aren’t worth shooting, but most of the time manufacturers include arrows in their bow packages to build perceived value. Many times these arrows are on the lower end of the spectrum when it comes to quality. So let’s take a more in depth look at the two types of arrow materials and what makes each one stand out over the other.
The first type of crossbow arrow we’ll look at is the aluminum arrow. Let me start out by saying if you are looking for the straightest, most consistent, most accurate arrow, then aluminum in your arrow. Aluminum arrow construction has been around for a very long time. The process of building an aluminum arrow shaft has been refined so well, that they just cannot be matched when it comes to consistency in both overall weight and spine deflexion. Especially when you mix aluminum arrow shafts from different batches. The consistency they provide just cannot be duplicated in a carbon arrow shaft. If that wasn’t good enough, aluminum arrows are also a good bit cheaper in price than carbon arrows too. I bet your thinking that aluminum arrows sound pretty darn good by now, but there are some areas of concern you should be aware of. First, is that aluminum arrows weigh more per inch than carbon arrows do. What this equates to is an overall heavier arrow. A heavier arrow translates into more kinetic energy which most times is a good thing, but because all crossbows have more than enough kinetic energy to begin with, it really becomes a moot point. That extra kinetic energy does translate into something else worth talking about. There is another misconception that aluminum arrows bend easily. While it is true that aluminum arrows can bend, it is usually not caused by normal everyday shooting. Where they do get bent is when a crossbow shooter is pulling them from a target while practicing. Because of the extra kinetic energy a crossbow produces, some crossbow specific targets have to be really dense. Especially the ones that stop broadheads. This in turn makes pulling the arrow from these dense targets very difficult at times. It is at this time, that most of the aluminum arrows get bent. Another time aluminum arrow can get bent is when you are group shooting while practicing. Sometimes, when shooting a very tight group, when one arrow shoots right next to another arrow in the target, the arrows can hit each other so hard that you can bend one or both of them, or sometimes even crease the wall of the aluminum arrow shaft. It won’t take you long with either aluminum or carbon arrows to realize you do not want to shoot at the same place twice. That is unless you don’t mind buying extra arrows all the time. If you do experience a slightly bent arrow from any of the above situations, the good news is that they can be straightened. An arrow straightener will be needed to do so, but almost every archery shop in the world will have an arrow straightener. If an aluminum arrow gets creased, do not use it anymore. It won’t fly right anyways and could possibly cause damage to your crossbow or injury to you. The other time that most aluminum crossbow arrows get bent is in a hunting situation after you shoot at an animal. If the arrow does not pass through the animal completely for some reason, then there is a good chance that the arrow can get bent from the animal either falling on it or from the animal running by trees with the arrow hitting them. Or if you do have a pass through, you don’t have any control on what the arrow is going to hit on the other side of the animal. There could be rocks or trees or who knows what in the ground. In either hunting situation, if the arrow does bend, I pretty much consider that part of hunting and in no way can blame the arrow for that. So just to recap, in normal shooting and practicing sessions with an aluminum crossbow arrow, you should never really bend one.
Another concern for aluminum arrows is the ability achieve a high front of center. Front of center is the ratio measured in a percent, of the forward weight of the arrow from it’s center point. Because there is no real way to tune a crossbow arrow like a vertical bow with an arrow rest, having a good front of center or FOC, is important for steering the arrow once shot from your bow. This really can come into play when shooting a broadhead, primarily a fixed bladed broadhead with a large cutting diameter. Fix bladed broadheads can have a tendency to want to plain when shot, but a heavier FOC can help correct this problem. In order to get a heavier FOC, you can either use a heavier broadhead or a heavier insert. Both will increase the weight of your arrow and as a result make your bow shoot slower. For some hunters, that’s perfectly fine, for others, speed of a crossbow is the main reason they will buy a particular bow. So they do not want to do anything to slow it down if they don’t have to. So in comes the carbon arrow.
Carbon crossbow arrows do have many benefits worth noting. First and foremost, they are lighter per inch than aluminum crossbow arrows. This in turn allows the hunter to use a much heavier insert to make up the weight and thus providing the higher front of center that we just discussed. We now know that this higher FOC will help steer the arrow down range more accurately, and also help with broadhead flight. So that is a big plus. Another positive attribute that carbon arrows provide is that they have the ability to bend and then return back to their original position. This means if you shoot a carbon crossbow arrow into a target and have a hard time removing it, you can really horse on it to get it out with little fear of damaging the arrow. Carbon arrows can crease like an aluminum arrow, however because the wall thickness of a carbon crossbow arrow shaft is much greater than that of an aluminum crossbow arrow shaft, the chances of creasing one is far less. So it would be safe to say the a carbon arrow shaft is more durable than the aluminum one.
Now lets take a look at accuracy. As stated before, no matter what type of arrow you choose to shoot from your bow, they should be accurate enough to hit your target at recommended hunting distances within 50 yards or less. But carbon arrows do have a couple of things that make them less consistent than aluminum crossbow arrows. This margin for error translates into an arrow that can still be accurate just not quite as accurate as aluminum arrows. First off, the way a carbon arrow shaft is manufactured does not provide for maximum repeatable accuracy. To help you understand why, we will first look at how a carbon arrow shaft is constructed. To produce a carbon arrow shaft, a manufacture actually takes strips of carbon or graphite and wraps them around a blank until it reaches the diameter the manufacturer specifies. Because there is a variation in the thickness of the materials used, some arrows will have more wraps than others. This normally isn’t that drastic or even worth mentioning when talking about arrow shafts from the same batch. But, if you were to buy a half dozen carbon arrows when you buy your crossbow and then another half dozen 6 months later, there will be a good chance that the two batches will weigh in differently and they may not even have the same point of impact. You do not see this fluctuation in aluminum arrows. Another issue with carbon crossbow arrows that can come into play is that unlike aluminum arrows that will have a consistent spine reading 360 degrees around the arrow shaft, carbon arrows normally have a stiff side and a weak side. Where this becomes a problem is that unless the manufacturer indexes the stiff side of the spine for every arrow, which at this point in time I only know of one manufacturer doing that, then you can have six arrows that are fletched differently according to spine that will all hit in a different spot, even from the same batch. This has been proven time and time again by hunters numbering their arrows and shooting them at a target. Then rotating there arrows 120 degrees to the next fletch and reshooting them until they find the position that each arrow shoots its best. I would consider this a super tuning method that the average hunter would never do, but it does work because there is a difference in spine when dealing with carbon arrow shafts. The difference may not be significant enough for you to care about, but there will be a difference. And once you screw a braodhead onto you arrow, it will be magnified.
So now we have a good understanding of the pros and cons between aluminum and carbon arrows. Which one should you use? That’s really up to you as a hunter. I personally use carbon crossbow arrows for hunting. I just feel that the advantage in front of center is enough for me to choose carbon. If I were going to just be shooting target competitions though, aluminum would be my arrow of choice.
Since we’ve already touched on front of center and arrow insert weight, will pickup there. The insert of a crossbow arrow is the piece of the arrow that you screw a practice point or a broadhead into. Inserts come in a variety of materials and weights. You can find carbon, aluminum, and brass inserts readily available for crossbow arrows. As rule, only aluminum crossbow arrows will have carbon inserts. Because they are so much lighter than aluminum or brass, the carbon insert helps keep the overall weight of the aluminum crossbow arrow down. The downside is that your FOC will be very low when using a carbon insert. Aluminum and brass inserts are the most common. Aluminum inserts are almost always found in aluminum arrows. Just like carbon inserts they help to keep the overall weight of the arrow down while providing decent FOC. Aluminum inserts are also sometimes found in carbon crossbow arrows. Depending on arrow manufacturer sometimes a beefed up aluminum insert designed just for crossbow use will be supplied. This special insert will be heavier than the standard insert that you would find for aluminum crossbow arrows. Because of the extra material, it weighs more which we now know will increase your front of center. The last type of insert is a brass insert. Brass inserts are the heaviest of all with many weighing over 100 grains by themselves. They provide the ultimate in FOC and are found in most of the carbon arrows. Especially the ones that have a low grain per inch weight.
On the flip side of a crossbow arrow you will find the arrow nock. Crossbow arrow nocks come in two main style with a newer third one that is a variation of one of the others. The most common types of crossbow arrow nocks are the flat nock and the moon nock, sometimes referred to as a half moon nock. The flat nock looks just as its name implies. It is simply just a flat plug at the end of the arrow shaft. The moon nock has a crescent shaped cut out that actually cradles the crossbow string. The third style is called a capture style nock. The capture style nock closely resembles a traditional arrow nock in the way it actually clips on around the string of your crossbow. To date only Parker Crossbows and Scorpyd Crossbows recommend using the capture nock along with the PSE TAC series crossbows. Out of the three type of nocks, only a crossbow arrow with a flat nock can be rotated so that you can shoot the arrow with any of the vanes in the downward position. With the other two types of nocks, the nock must be correctly indexed to the string. Not doing so can result in a partial or complete dry-fire of your bow. You can however shoot a crossbow arrow with a moon nock or a capture nock from a bow that specifies a flat nock. You cannot however, shoot a flat nock from a bow that specifies a moon nock or capture nock. It is a good idea to check with the manufacturer of your crossbow before purchasing arrows to make sure you are following their recommendations on what nock type to use.
Crossbow arrow nocks can be made from aluminum or plastic. Plastic nocks weigh less than aluminum nocks do which helps the overall FOC of your arrow. Aluminum nocks are heavier but also stronger. Some of todays bows that have a high amount of stored energy have been known to crack or break plastic moon nocks just from normal shooting. So some crossbow hunters are switching to aluminum moon nocks for the extra insurance. I should point out that no matter what type of nock your arrow has, you should make it a habit to inspect each one after shooting, particularity if you are group shooting which has a higher risk of damaging nocks from being hit by other arrows.
On the tail end of the arrow you find the fletching. Fletching are the guides at the back of an arrow that help to stabilized and guide the arrow in flight. Fletchings can be made from plastic or feathers, but plastic fletching, also called vanes, are most popular do to their durability. Fletching is normally set offset from parallel to the arrow shaft in order to create a slight drag which then make the arrow spin. The spinning of your arrow is important to achieving good flight. An arrow that spins will recover from arrow oscillation, known as archers paradox, quicker than an arrow that doesn’t spin. The faster an arrow corrects itself from oscillating the more accurate it will be down range. So it is important to have some offset or helical when it comes to fletching. There is no rule as to how much is enough and how much is too much. A couple of factors that will determine how much you can have is the width of the track in the rail of your crossbow, and the length of your vanes.
Most arrows come pre fletched with either 4” or 5” long vanes. While some crossbow arrow manufacturers are starting to use a shorter, higher profile vane such as a Bohning Blazer vane or Fusion Vane. The current trend for those hunters that fletch their own arrows it to use the shorter vanes. Besides just looking cool, the short crossbow vanes seem to do well with bows for a couple of specific reasons. The first and most important goes back what I keep referring to for reaching optimal crossbow arrow flight, that is FOC. The shorter the vane, the lighter it weighs. Just how adding weight to the front of the arrow with heavier inserts or points increases FOC, taking weight away from the back of the arrow will also hep your front of center. By using the shorter vanes you can eliminate weight from the rear of the arrow, but because they are a little higher profile than the longer vanes, they still steer they arrow very well. One thing to note is that the depth of the track in a crossbow rail is not equal across all manufacturers. Some of the highest profile vanes can and do hit the bottom of the rail. This can cause the arrow to kick up and down when leaving the crossbow. This arrow flight characteristic is known as porpesing and is not good. It will effect the way arrow flies and you will loose accuracy because of it. You should be able to see it with the naked eye on extreme cases. You should also be able to inspect your cock vane, or the vane that rides in the rail, to see if you are getting contact. If you are, I would recommend using a different vane.
Another reason short vanes are so well liked on crossbow arrows is because they give your arrow more length to penetrate the target before ruining the fletching. Crossbow arrows are shorter than most vertical bow arrows. Because of this, combined with having more kinetic energy, crossbow arrows penetrate deeper into most targets. When this happens, you will often damage the vanes. Sometimes that can just wrinkle on you but sometimes that can rip off too. So by eliminating 2”-3” of material from your vanes by using the shorter length vanes, it allows your arrow to penetrate 2”-3” more before damaging them. Doesn’t seem like a big deal, but it will save you time and money in reflecting jobs.
Arrow length is an important factor that should not be over looked. Most manufacturers either specify a 20” or a 22” long arrow. There are a couple reasons for this. Safety is one reason. When you properly load a crossbow, you should insert the arrow from the front of rail and push it down towards the trigger housing. The reason for this is that incase there ever was a failure, your hand would be out of the path of the string and it would help you to avoid injury. By making the arrow longer than the rail itself, it gives the crossbow hunter something to hold onto in forward from the point the crossbow string would comes to if it did accidentally fire during the loading process. The length of each arrow is specified by the manufacturer. A factor that does come into play on how long that arrow is is how long the power stroke of the crossbow is. Generally the crossbows with longer power strokes will shoot the longer 22” arrow. Overall arrow weight is another factor. Every crossbow manufacturer also specifies what the total minimum arrow weight should be for their crossbows. Even though many bows may be able to shoot a shorter arrow than what is specified, they need the extra length in order to get the total arrow weight up to minimum standards. It should be noted that even if a shorter arrow meets your crossbow manufacturers specifications in minimum arrow weight, doing so can void your warranty and possibly cause bodily injury.
The last part of a crossbow arrow is the point or tip. An arrow can be tipped with a practice point often called a field point or bullet point, or a tip with sharpened blades on it used for hunting called a broadhead. I will have a future article dedicated to broadheads, so I won’t spend much time on them here. So that leaves the field point. Theres not a lot that can be said about the field point. They come in a few different shapes and sizes. The most important thing to know is that you should use the same weight field point to practice, as the weight of the broadhead you will use to hunt with. Even then, your broadheads may still not hit in the same point as your practice points. So it’s a good idea to practice with your braodheads before going afield.
Since the time I wrote this article, there has been an introduction of a new crossbow nock. There are now two manufacturers making what I would call a hybrid nock. That is a nock like a moon nock but with grooves in it every 120 degrees. The advantage of this over the moon style nocks is that the arrow can be rotated to shoot any vane without the worry of having a misalignment as discusses in the article above.
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