Introduction guide to crossbow big game hunting

Big game hunting requires a lot of practice and specific knowledge to the throwing weapons used. Rifle hunting and crossbow hunting are diametrically opposed.

In the case of a firearm, a high speed propelled projectile is used, creating a kinetic energy and hydrostatic effect that will transfer to the beast when the projectile expands on impact. This shock will damage several vital tissues in the penetration channel and cause rapid death. In the case of the crossbow, the blades on the hunting points will cut off tissues, blood vessels and vital organs, causing a fatal hemorrhage in the vital area. So, deeper the arrow penetrates, that means through the animal, more blood will be lost and faster the animal will die, which will make it easier to find.

In the following pages, we present tips and tricks, as well as information tables to help you to use your crossbow properly and in a responsible way.

Examining the crossbows of the tests, we found repeatedly that the cams were not synchronized, that the spring tension on the boom was too high (which causes the tip of the arrow and the arrow to tip upwards that the screws of the telescopic sight, that the branches, pulleys and other components were loose and that the ropes and their wire-slice were worn or broken. This helps to decrease the accuracy on several crossbows and can create an erratic shot.

The retention spring can be broken or bent if a wrong stretching technique is used. We must arm the crossbow by the drawstring backwards, or towards the hips.

However, a 2.5 cm (1 “) lateral gap in the draw cord did not cause any scattering of the arrow grouping to the target. Adding a little lubricant on the deck helps to reduce adhesions and, thus, to obtain a better grouping, because the speed of the arrows is more constant. But an excessive amount of lubricant can lose up to 10% of the speed, thus changing the ballistics.

Finally, when shooting, stay still and watch through your telescope the arrow penetrate the vital area. In this way, you will get greater accuracy.

The manufacturing standards for firearms and ammunition ensure that each cartridge of the same caliber of equal weight draws approximately 2 to 15 cm (3/4 to 6 inches) in the same spot from one mark to the other. other at 100 meters.

For their part, crossbow hunters must assemble their own combination of arrows and hunting spikes. If the combination is not balanced, the point of impact may vary from 5 to 30 cm (2 to 12 inches) at a distance of 30 meters.

We measured 50 new carbon arrows and all of them had warp distortion ranging from 0.001 to 0.010 inches; this irregularity will change the point of impact.

Fixed or retractable 2, 3 or 4 blade hunting tips do not have the same point of impact as practice tips.

Broken or warped feathers change the point of impact from 2 to 5 cm (3/4 to 2 inches), also opening the grouping by 30% to 30 meters. One or two altered feathers create an asymmetry having more influence on the opening of the grouping than a break on the 3 empenels at the same time.

The grouping widens by 5% if the mass of the arrows of an assortment varies of 10%. Also, the weight of the arrows varies the point of impact; you have to number the arrows to identify them.

The crossbow is not a gun.

Hunting points do not act in game such as the projectile or bullet of a firearm.

The projectile has a blunt effect with high energy transfer during the impact, it will expand in the beast (the famous “mushroom”). A good retention of the ball will allow it to transfer all his energy to break the flesh and produce a hydrostatic effect.

A flush arrow requires 16 times less energy to drop a moose (about 90 lb-ft for the arrow versus 1500 lb-ft for the shot) because it works by cutting flesh, blood vessels, and organs vital on a large area without deformation of the blades. The damage inflicted is therefore first hemorrhagic. It becomes advantageous for the arrow to cross the animal from side to side to maximize blood loss and facilitate research.

Some reflexes developed in hunting with firearms are not transposable to hunting with crossbow.

The center of the vital zone (heart, liver and lungs) remains the only acceptable point of aim, in perpendicular fire and when the game is motionless.

A reticle allows, in an optical device, to perform more accurate sighting by single or multiple cross threads drawing a marker that allows alignments.

There are 2 types of scopes, either fixed or variable power. The sight of the telescope is mounted with horizontal lines (bars), points, small circles or small triangles that will be used as reference to the point of impact according to the shooting distance.

We observed models where the bars are all at the same distance and others whose height between them changes, as much for the fixed ones as for the variables. In addition, in the case of riflescopes with variable power (often represented in speed arrows), the height of the bars changes with the power transmitted to the arrow.

So, if your center reticle is adjusted for a shot at 15m, it is essential to validate how far bars 1, 2 and 3 compensate for reaching the target at 20, 25 and 30m. We observed differences of 10 cm and more between the points of impact of the arrows in the target.

The following table presents the results of our experiments without modification of the hunters sighting scope already adjusted from 18 to 32 m.

Table 1: Vertical position (in cm) of impact of the arrows in the target according to the reticle line (bar) selected in the sight;
Test from a distance of 30 cm.

Warning: Magnification makes the target look closer, but does not change the behavior of the arrow.

The typical hunting arrow follows the path (black curve) shown below. This curve must intercept the channel of the game’s vital zone, shown in green for the deer (diameter of 20 cm) and in yellow for the moose (diameter of 40 cm).

For example, with a 400-grain arrow starting at 350 feet per second: to ensure that the flight of the arrow remains in the vital area without correcting the aim, a maximum distance of 26 meters must be kill a deer and just over 30 meters for a moose.

Graph 1 : Trajectory

The trajectory of an arrow curves much faster than that of a firearm projectile, so every meter distance makes a difference to crossbow shooting and the use of the rangefinder is paramount.

The watch tower shots were fired at a height of 4.1 meters, and at distances of 20 and 30 meters. Comparative shots horizontally, at the same distance, make it possible to understand the effect of the height difference of the watchtower, by comparing the targets.

To the great surprise, no matter the speed, the point of impact does not fall more than 5 cm between the horizontal shot and that made in the watch tower. The effect is more noticeable at a medium distance (20 m) than at a greater distance (30 m), as the angle down is more pronounced at 20 m. Because of this angle, it is necessary to move the point of sight a little higher towards the back of the animal. It is necessary to visualize the passage of the arrow in the vital zone.

Although the point of impact moves slightly, the group remains the same during a shot in a watchtower as when shooting horizontally.

However, beyond 30 meters, the fall of the boom becomes larger, reaching 30 cm.

One more reason not to exceed 30 meters shooting distance so as not to miss the vital area of the game.

Shots on parts of animal carcasses show that a poorly-lodged spire will not have a lethal effect in the short term given the low energy and action of crossbow arrows. Thus, the hunting spikes that met the bone of the shoulder pad broke or simply deviated.

It is therefore useless to draw on the animal in other parts than the vital zone. Also consider that a major part of this heart-liver-lungs spongy area is protected by rigid ribs (rib cage). The arrow must have good energy to cross this natural barrier: make sure to shoot when you are near the game, within 30 meters.

Branches

A hunter, eager to seize an opportunity, sometimes pulls when the game is not visually clear, that is to say when it is positioned behind shrubs (even very small).

Such a practice is to be avoided for several reasons, besides the dangerousness of the thing. First, the blades retractable are not very resistant to the passage in the branches. Some literally broke in pieces during testing.

Even the use of fixed hunting blades does not solve the other problems: the points of impact varied by several centimeters and, especially, the groups of arrows of the same fly had impressive dispersions sometimes approaching the 2.5 meters!

What are the probabilities of reaching the vital zone? The table at the end of this section summarizes the situation.

The wind

Our tests were made with a wind simulation of 17.7 km per hour perpendicular to the direction of fire.

A wind that comes about halfway (14 m) on the track has little impact on the grouping and almost none on the point of impact because the boom in flight has already stabilized.

However, the same wind acting 4.5 m from the shooter has a detrimental effect on the point of impact and the grouping. In particular, the grouping can widen by 1 or 2 meters!
It is therefore important to know how to “read” the wind to compensate for its effect with the turrets of the telescope or by offsetting the point of aim.

Table 2:Percentage of probability of missing the vital area by considering the dispersion of the grouping of arrows.

Conclusion
The shooter is therefore 80 to 99% risk of missing the vital area.

A responsible hunter will wait until the animal is stationary and well positioned to aim for the center of the vital zone.

The call of the deer females reaches a loudness of about 60 decibels and the crossbows release with a sound of an average located in the 90 decibels, in spite of parts integrated on the weapon to attenuate the sound effects.

Since crossbow shooting is conducted at a short distance and at low speed (as opposed to shooting with a firearm), it is evident that the game hears the release including the ultra-high frequency vibrations and attempts to flee, lie down or jump before the arrow reaches it. The speed of the white-tailed deer allows it to flee, unlike moose, if the shot is fired at a suitable distance (less than 30 m).

How to fix the problem? Shooting at a greater distance to smother the noise is impossible: it would take a huge distance to deceive the deer. The speed of the arrow is only slightly modifiable and can not be increased to reach that of the sound, which exceeds 1050 feet per second.

On the contrary, it is necessaryto approachthe deer to reduce the time interval between the arrival of the sound to his ear and the impact of the arrow in the beast.

If this interval is shorter than the reflex time of the animal (four times faster than that of the man), our chances of reaching it in the vital zone increases

Table 3:Firing distance on deer taking into account the animal’s hearing and reflex time (without any other negative factors).

Note: The penetration and the trajectory of the arrow to more than 30 m risk of simply hurting your beast, for lack of kinetic energy.

• Examine cracks, color changes on your branches (sign of weakness);
• Check the width of the branches of your crossbow without tension to validate the safe space in your caches;
• Tighten all screws properly and seal the screw head;
• If your crossbow is not equipped with a finger protector, be careful when pulling (keep the fingers of the carrying hand under the arbrier (bridge));
• Validate the warping of your arrows by rolling them on a flat surface;
• Ideally align your fixed hunting points with your feathers;
• Check that the notch is 90 degrees with the cock feather;
• Always check that your arrow is touching the rope before firing to avoid empty shooting (can cause serious injury to the shooter);
• Check if the arrow has cracks.

• Rangefinder
• Carrying case (rigid or flexible)
• Quiver
• 6 identical arrows (length, thickness, mass)
• 6 identical hunting blades (mass) (fixed or retractable)
• 6 practice points of the same gravity as your hunting spikes
• Rope wax
• Lubricant for bridge (arbrier)
• Hexagon key
• Spare rope already stretched
• Tensioner rope (stretching system)
• Extension cord
• Arrow puller
• Accessory (key) to change the tips
• Lens cleaner and wipe
• Battery (telescopic sight, laser rangefinder)
• High density styrofoam block
• Surveyor’s tape (biodegradable if possible)

It may be necessary to use a dog-dog driver and his animal to find wounded game, especially if visual cues are non-existent or difficult to interpret.

From the ethical point of view and for your recovery, the blood dog is an ESSENTIAL in the search for a game wounded (mortally).

In addition, for a negligible amount of money, you will save a game of hunting that cost you a lot more.

For any information, you can visit the website http://www.accsq.com/

After using 6 different crossbows and shooting more than 300 arrows, we can see that the crossbow is performing with arrows of equal weight and short distance, up to 30 meters. For distances greater than 30 meters, the use of the rangefinder is essential, and the risk of injury to the animal increases greatly, due to the wind, changes in impact points, differences in the weight of the arrows, errors in purpose caused by the multiple sight reference lines on the reticle of the telescope, the instability of the shooter and, above all, the insufficient penetration of the arrow to pierce the body of the beast in the vital zone from apart to promote blood flow and facilitate the search for game.

In conclusion, during your shooting practice, you should always check and shoot the same arrows and tips of (practice and hunting) that you will use in the hunt, and this, by wearing your hunting clothes if possible.

The success of your shooting will depend on your practice shooting at different distances, and in different climatic conditions, not to mention the stability of the weapon.

Each year, thousands of crossbow hunters criss-cross big game hunting grounds to harvest their animals from the start of the hunting season. Especially since it is the best time of the year, that of moose rut, depending on the area.

The very nature of the crossbow requires a lot of knowledge and experience on the part of the hunter with his equipment, in order to make his shot on the first try and thus to avoid hurting or even losing an injured animal. As a bonus, the venison will be of better quality.
Many tests were conducted at different distances and in different textures, which helped to better understand the characteristics of this weapon and to develop the recommendations and tips contained in this guide.

Prepared by:
Marius De Champlain, firing monitor
Suzanne Desjardins, B. Sc. Physique and instructor
Louis Hébert, teacher and monitor

Developed with
ZEC Bas-Saint-Laurent : 418-723-5766
Club de tir du Bas Saint-Laurent : 418-725-4570

Our thanks:
Jeannot Ruel
Ernie Wells
ACCSQ 11/2016

Reproduction is prohibited without prior permission.