The evolution of the crossbow over the centuries has seen the power factor increase significantly. The gradual increase in draw weights rendered more power resulting in more distance and more impact on the target, etc. As power increased, the effort to pull back on the string became too much for most people to manage. As a result, several different kinds of cocking devices were used to enable the arming of a crossbow to be managed with much less effort. Broken down into their most basic form, these cocking devices include manual or hand cocking of the bow string; rope cocking method; and, cranking device method. I will deal with each method below and mention some of their advantages and disadvantages.
Hand or manual cocking was, of course, the initial method used and is still used today for lighter crossbow draw weights. This required the bowman to place his foot in the stirrup, reach down with two hands and pull the string back to its cocked position. Sounds simple! However, if a crossbow draw weight is 125#’s it takes the same effort to cock the string as to lift a 125# weight straight up. Very much like lifting a bar bell from a standing or bent over position. Tough to do and tough on the back!
Yet another problem with the manual method for cocking a crossbow is the need to draw the string back very straight. If it is not drawn back correctly your accuracy will be negatively affected. By pulling one side with more strength than the other, the string will pull the arrow or bolt to one side or the other when released. With modern more powerful crossbows, up to 200# pull and more, this is not the preferred method for most people (unless, of course, you are a fan of lifting heavy weights while hunting). There is an advantage though. If you are able to handle the draw weight, you can cock the bow and be ready to fire in as little as 10 to 15 seconds. Another advantage is that you do not have to purchase any additional gear, or cocking device, or to carry it into the woods. You might want to consider the following suggestion. If you plan to use the manual method of cocking your crossbow, make a mark in the exact center of your string to help assure consistent accuracy in your shooting.
The second method for cocking your crossbow is to use a specially designed rope cocking device. These cocking devices use two handles and two string clips attached to the pull rope. In addition, a pulley system is employed to increase mechanical advantage. This permits the strength needed to cock the crossbow to be cut in half. Instead of pulling the string up with say 150 #’s of strength it is reduced to 75#’s of pull. This still requires strength but only half as much. However, because of the mechanical advantage of using cocking devices with a pulley system, you will have to pull the draw rope twice the distance traveled by the bow string.
One advantage of the various rope cocking devices is their relative low cost. Typically from $25 to $40 will purchase a very serviceable unit. Another advantage is that it takes half the strength to cock your crossbow. It also centers your string at full draw which improves the accuracy of your shot. It’s still a good idea to mark the center of your bow string to be certain there will be even force exerted on your arrow when it is released. With your foot in the stirrup, you can cock your crossbow using a rope cocking devise in around 30 seconds and be ready quickly for your next shot.
I suppose the few real disadvantages of using a rope cocking device is the additional cost to purchase it, the few seconds more it takes to cock the bow and having to keep it on your person for quick access while hunting. We strongly recommend this simple and inexpensive cocking device be a part of every crossbow hunters gear. It works well and one can become very skilled in its use with a little practice.
There are also several kinds of crank type cocking devices on the market designed to reduce the effort needed to bring the string into firing position. Some of these cocking devices are permanently attached to the stock of the crossbow while others need to be attached in the field as needed. Both types require a crank or winch type mechanism to draw the string back into position for firing. The mechanical advantage of this type of device is very significant. It usually takes about 10#’s of pressure or less to cock a powerful bow. That means that a 175# or even a 200# bow can be cocked by someone of much lesser strength or with some physical limitations.
As noted above, a significant advantage of the crank type cocking device is the rather small amount of strength that is needed to load the crossbow. These cocking devices do a very good job of keeping the string centered when cocked and increases accuracy as a result. One more important advantage is that it permits shooters and hunters with restricted physical abilities to enjoy the pleasure of using a crossbow.
Finally, one must be aware that while there are some very important advantages to a cranking device for cocking a crossbow, there are some disadvantages as well. The cost of these devices can be above $120. They tend to be somewhat heavy and bulky to carry in the field. Though it takes little strength to use a cranking device, it could easily take 2 or 3 minutes to complete the cocking procedure. Those models that are not permanently attached to the stock or handle of a crossbow need to be mounted, used and removed after use. This can clearly make a rapid second shot virtually impossible.