It’s once a year, it’s longed for and the anticipation building up to it can make even the most experienced sportsman feel anxious. It’s opening day. There is much to do before then, and hunting with a crossbow is no different. Scouting your area and buying licenses are a must, but you should also check over your gear and ensure your arrows are flying true. There is no bigger disappointment to a hunter than missing. To help avoid this, take the necessary steps in advance of the season opener to ensure your crossbow is sighted in before you step into the field.
If you’ve recently acquired a crossbow and this will be your first season using it, take the time to read the manual. They’re only a few pages long and contain lots of information specific to your crossbow manufacturer and model. Instructions on assembly, safety, cocking and un-cocking, maintenance, warranty, arrow specifications and scope calibration will all be included. If you haven’t done it already, mail in your warranty information.
Assembly is short and sweet. The string is usually strung onto the limbs and will need to be mounted to stock, if it’s not done already. Once the bow part (string and limbs) is mounted perpendicular on top of the stock, it’ll resemble a crossbow and is likely ready to shoot bare with help from your cocking device. However, most come with accessories these days, such as quivers, scopes and mechanical cocking devices. As usual, just follow the instructions and your crossbow will be completely assembled in no time.
Going hand-in-hand with the weapon itself are the things it shoots. In this case, short arrows (also known as bolts). Crossbow arrow specifications will have several components – all are important and all are found in your manual. The arrow shaft is made from carbon fibre these days. It’s great material to make strong, flexible, straight arrows. I wouldn’t consider anything else, even if you can manage to find it. The most crucial property is the spine, which is the stiffness of the shaft. A correct spine will capture all the energy transferred from the limbs/string when fired. An incorrect spine will not and can be very dangerous when too weak, meaning the arrow can break in half when fired.
Arrow weight is also very important, but tightly coupled with length. The most important aspect of length is that the arrow tip (especially a broadhead) will not touch the rail when the crossbow is cocked and ready to fire. Arrows are sold with a grains-per-inch (GPI) value. Crossbow arrow lengths vary from 16 to 22 inches. Your manual will specify an optimal total arrow weight. Your arrow weight is made up of five parts: shaft (GPI), tip, nock, fletchings (vanes) and inserts. Vanes, aluminum inserts and nocks barely weigh anything, so your main factors will be the GPI and tip. I used a digital scale to weigh my arrows and tips to ensure I met the manufacturer’s recommendations. Unfortunately, my scale was in grams, so I converted to grains by dividing the grams by 0.0648.
Three vanes per arrow are recommended, with a straight pattern. The nocks will either be flat or half-moon. Half-moon design helps to prevent the string from slipping off, which would result in a dry-fire. Dry firing a crossbow means that you’ll need to get it inspected to ensure nothing was damaged. Again, consult your manual for the recommended nock style designed for your crossbow. You just don’t want to take a chance using an incorrect nock, as it’s a vital interface between the string and arrow. In my case, the Mission MXB-400 manual recommends Mission branded bolts/arrow that meet the following minimum specifications:
- Half-moon aluminum nocks
- 1.35 inches of clearance between the inside of the nock to the beginning of the vane
- A total weight with tip of 375 grains
- 22 inches in length.
For example, my arrows, which meet the minimum requirements, are composed of the following components:
- 22-inch carbon fibre shaft (11.61 GPI) [22 x 11.61 = 255.42 grains]
- Three four-inch plastic vanes [3 x 10.8 = 32.6 grains]
- One aluminum insert [14.2 grains]
- One aluminum half-moon nock [13.9 grains]
- One arrow tip [150 grains]
My arrow weight totals 466.12 grains, which means I could still use a 100-grain tip, instead of a 150-grain, and meet the manufacturer’s minimum. However, I sighted in already with 150-grain field points and tested with broadheads.
Sighting in your scope requires four initial steps: mounting, adjusting the ocular lens, initial zeroing and calibrating. The first two steps don’t require discharging an arrow and are quick and painless. First, place the un-cocked crossbow on a sturdy work surface and position the scope on a set of rings along the rail. Now shoulder the crossbow to test the eye relief and adjust accordingly. The optimal position is when you shoulder the crossbow in your normal shooting position and a full sight picture is viewed without straining, tilting or stretching your neck or head. Next, rotate the scope until the horizontal crosswire is parallel with the crossbow string and limbs when you look through the scope. Tighten securely as a last step.
The second quick adjustment is to set the focus of the reticle. Do this in similar light and condition and at a distance you’ll be shooting at, likely 30 to 50 metres. Usually, the scope’s ocular lens housing will rotate back forth to make the focus as sharp as possible. One final test is to shoulder the crossbow into shooting position and the entire field of view through the scope should be in perfect focus. You’re ready to start shooting.
The latter half of sighting in your crossbow requires that you shoot arrows into a stable target. You must zero in, which means to have the point of aiming (POA) equal the point of impact (POI). Pace off 10 yards and take a shot with a field point. Remove the dust caps from the windage (left/right or east/west) and elevation (up/down or north/south) turrets of the scope and make the appropriate clicks (adjustments) to bring the POA closer to the POI. Shoot another bolt and repeat the adjustment process. When the POA equals the POI, step back to 20 yards to try again. Do the same process for aiming and adjusting until POA equals POI at that further distance. When complete, put the turret covers back on.
The final step is to calibrate the scope. Turn the speed selector to the manufacturer’s advertised speed of your crossbow. Pace off 30 yards. Aim using the 30-yard marker in the scope (second crosswire down) and shoot. If the arrow impacts high, turn the speed selector higher by 10 feet per second (FPS) and shoot again. Do the opposite if the arrow impacts lower. Once the POA equals the POI, your crossbow is calibrated for all other aiming points (40, 50 and 60 yards) in your scope. At this point, you should no longer have to adjust the turrets or the speed selector. They should remain untouched unless your target practice is not going as expected. You should be able to shoot three or four arrows into a practice target and have them touch each other or be very close.
At this point, you should apply some rail lube to the rail and continue to do so after every 10 shots forever. This will help maintain your string and extend its life. Before stepping into the field for hunting, you should sacrifice one broadhead tip and file it down so it isn’t as sharp and ensure it’s flying as your field tips do. If by chance it isn’t, try another broadhead for starters, perhaps even a mechanical.
The only other caution I’d like to mention is that bows can shoot different depending on drastic temperature changes, so if you’re getting into late season hunting, it’s best to practice in hunting-like conditions to ensure there are no surprises come the moment of truth. Good luck everyone!