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Optics For Your Crossbow - Scope Out The Possibilities
2008-06-08
A question that is often asked by a new crossbow shooter is “If my hunting shots are going to likely occur at 30 yards or less, why on earth would I use a magnified scope on my crossbow? Not a bad question!
The answer is of course, you don’t need magnification in your sight to be effective in the field, but if you’re like the majority of crossbow hunters, you may find that a magnified scope is the best choice for your shooting and hunting needs. Let’s explore why this is true and what factors need to be considered in choosing a scope to best match the shooting characteristics of a crossbow.
First, what are the advantages of a scope over other sighting options?
Probably the number one advantage of a scope to most hunters today is familiarity. Because the majority of crossbow hunters are also rifle shooters, setting up your crossbow like your favorite deer rifle is a natural occurrence. Most rifle shooters are just more comfortable shooting with a scope. Also, many shooters find their eyesight isn’t what it used to be and open sights are difficult to see clearly-especially in low light conditions. All rifle type scopes contain a focus adjustment in the eyepiece to deliver precise focus of the lenses and reticle whether you wear corrective lenses or not.
Second, Light Gathering
I am sure that you have observed big game, especially from a treestand, during the last thirty minutes of legal shooting time. It is amazing how the animal’s natural camoflage can make them magically blend into their background at this time of day. A scope really shows its value at this time, enabling you to distinguish detail and “pick a spot” during this critical time of your hunt. Even mid-priced models in low magnification will help. If you’re looking for the ultimate in light gathering, consider top quality offerings, perhaps even with a 30mm tube rather than 1” and keep the magnification to 4x or less.
Third, Reticle Choices
There seems to be an unlimited array of reticles out there to choose from. If hunting is your main application, remember to keep the reticle bold and easily acquired. Some of the European styles with heavy bottom posts are extremely effective. If your crossbow has a fixed sight bridge, you definitely want to consider a multiple crosshair reticle. Otherwise, you will be limited to precise aiming at just one yardage. If this is the case, sight your bow in to hit dead on at 25 yards. This will keep the amount of hold over and under at practical hunting ranges to a minimum. If your crossbow features an adjustable mount, like the Horton Dial-A-Range, a single crosshair scope (with a little practice and experimentation) can serve quite effectively.
Be cautious, however, with just any multiple crosshair offering. Some so-called “crossbow” scopes utilize an outdated South African reticle design that is totally ineffective on most modern crossbows. With the main crosshair sighted in dead on at 20 yards puts the impact of the second crosshair at almost 50 yards! A properly designed multiple crosshair design should yield approximately a 10-yard difference in trajectory between crosshairs.
Fourth, Eye Relief
Eye relief is the distance measured in inches, from your eye to the eyepiece of the scope that produces a full image when sighting through the scope. Most rifle scopes designed for use with high powered rifles will feature eye relief’s in the 4” to 5” range to keep the scope safely away from the eye during heavy recoil. Of course, crossbows do not kick heavily rearward so long eye reliefs are not required. In fact, many crossbow stock designs will not allow mounting the scope forward enough to provide comfortable positioning. Ideally, eye relief of your crossbow scope is in the 2 ½” to 3 ½” range .
Fifth, Recoil
The recoil of a crossbow is quite unique. Not only is there the initial forward movement (opposite that of a rifle), but also after the arrow leaves the string, rebounding recoil occurs. Then, this forward and rearward recoil reoccurs, over and over, many times until the limbs, string, and cables (in a compound bow) finally come to a rest. This type of recoil (which is also a characteristic of air rifles) can be quite destructive to optics. Without proper construction and design, crossbows will destroy a scope in very few shots. I have witnessed scopes that retail for over $300.00 not survive 20 shots!
Sixth, Magnification
Although Americans generally consider “more is better”, nothing could be farther from the truth when choosing and effective scope for crossbow use. Shooting with too much magnification in the field cuts down on the available light a scope can gather. It also reduces a scope’s field of view and shows the shooter excessive aiming movement, which leads to all sorts of shooting problems, which we will discuss at a later date. In fixed power, 2-½X to 4X is ideal and 1-½X to 5X in a variable model should prove to be an excellent choice.
Finally, Parallax
Parallax is basically the focusing of the reticle at a given distance. In most scopes designed for rifles, the factory will preset this adjustment at 150 yards. Ideally, a crossbow scope’s parallax adjustment should be set at 50 yards. Some offerings today will feature adjustable objective lenses. If you already own a high quality scope that you would like to mount on your crossbow, consider having the parallax changed to 50 yards by the factory. I once had Leopold perform this service for me on a dandy 3X fixed power. I believe the fee for this job was around $25.00.
When preparing your crossbow for this season’s hunt, consider topping it with a good quality scope. You’ll be glad you did.
Have a safe and successful Hunt!
Mark
About the author: Mark Bower, COO of Horton brings 40 years of archery hunting, shooting and manufacturing experience to Horton. A former National Archery Champion, Mark has hunted worldwide harvesting 19 species of big game and over 100 Whitetails with archery gear. Mark’s passion is helping others to achieve success and to enhance their outdoor experiences. When not working with crossbows and Vertical bows, Mark enjoys fly fishing and bird dog training with his family.
