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If you’re thinking of investing in a caliper release for your bow, you’ve likely seen both single and double caliper releases. You may be wondering, “what’s the difference?”
This article will help you to understand the difference between different types of releases and select the release that’s right for you.
Is a single or double caliper release better?
Ultimately, this is a question of personal preference. A single caliper tends to give a more consistent release shot to shot. A double caliper provides a more even release of tension. Which you prefer is going to depend on your personal shooting style.
Before we can get into greater detail about the differences between the two, we first need to go over what exactly a caliper on the release is.
What is a Caliper?
Merriam Webster defines caliper as “any of various measuring instruments having two usually adjustable arms, legs, or jaws.” Essentially, a caliper is a set of jaws that grabs or measures things.
In our case, the caliper will be holding and releasing the D-loop on your bowstring. Using a caliper release assist will give you a far more consistent and reliable release than simply holding on and letting go with your fingers.
On releases, calipers can be either single or double—meaning that there is either a single moving arm or two arms moving together. What does this mean in terms of your shot? Are you going to prefer a single or double release? First, we’ll go over the specifics of a single caliper release.
Single Caliper Release
A single caliper release has just one moving arm that releases hold on the D-loop. The biggest advantage of the single caliper release is consistency. Because there’s only one point of motion, you can feel certain that the bowstring is going to be released the same way every time.
An example of a single caliper release is the T.R.U. Ball Stinger, shown here:
The other major advantage of a single caliper release is durability. Because there are less moving parts, there are fewer pieces that can potentially get broken and cause the release to need repair or replacement.
A single caliper release is easier to maintain and functions more reliably in bad weather.
Double Caliper Release
A double caliper release has two moving arms that pull back simultaneously to release the bowstring.
The main advantage of a double caliper release is that it releases the tension on the bowstring more evenly. The more even distribution of friction on the bowstring provides a cleaner release and reduces torque.
An example of a double caliper release is the Tru-Fire Edge, shown here:
The main reason that people stray away from double caliper releases is that with two moving parts, the bowstring may release slightly differently each time you shoot, depending on whether the bowstring releases more off the top caliper or the bottom caliper. This may result in some small degree of lost consistency.
Some people do report that double caliper releases cause more wear and tear on their D-loops. If you do decide to go the double caliper route, you may want to plan on replacing your D-loop pretty regularly.
It’s important to note that the double caliper seems to be the more popular of the two options and you’ll find a wider array of double caliper release aids on the market.
Which is Better for You?
Again, a single caliper vs a double is really a matter of personal preference. Neither one is inherently better than the other. Try out both on a few different releases and see what feels best for you.
If you’re first starting out it may be worth considering using a double caliper as they’re considerably more forgiving than single caliper releases. The double calipers are a little less touchy and this will allow beginners to use more of their focus on essential elements like aim and draw length.
It may be worthwhile to move to try out the more sensitive single caliper release as you become more adept at shooting.
This being said, if you’re already used to one style or the other, you almost certainly don’t want to switch it up just for the heck of it.
Your body builds up muscle memory over time and any adjustment will take time to get used to. When a release breaks or goes bad on you, that’s a good time to switch things up, as you’ll need to adjust to a new release anyway.
The differences between single caliper and double caliper are pretty slight and it’s important to remember that this is only one of several factors that play into deciding on which release to purchase.
Other options to consider on releases are the style, the strap, and the connector. All of these components are important to consider and weigh as you’re selecting a release aid.
Release aids come in a number of different styles, including an index finger release, a thumb release, or a back tension release.
The primary difference between these styles is that the finger releases are activated by pressing a button or trigger, while the back tension release is activated by engaging of the shooter’s back muscles as the bowstring is pulled back.
Index finger releases may be the most popular because of the intuitiveness and familiarity of pulling on a trigger with the index finger.
Many releases with index finger triggers allow for a great deal of customization on where the trigger is placed and how much force is needed for it to engage.
The low barriers to entry, combined with adjustability for maximum comfort make this style the most popular on the market.
The biggest issue with index finger releases is that they can activate prematurely if the shooter clenches their fingers due to target panic. Many shooters, bowhunters especially, employ a thumb button which gives more control to the bowman.
The thumb button gives the archer time to check their stance, draw, anchor, and aim before punching the trigger. Thumb releases can help hunters overcome the impulse to “shoot now!” when a target is right in front of them.
Back tension releases dial this up another notch by using the tension created by the draw to release the knocked arrow. Because the hunter isn’t directly controlling the release, the release comes as a surprise, preventing the archer from tensing up before the anticipated release.
Back tension releases generally give the greatest accuracy but are the least intuitive and take the most getting used to.
While many hunters swear by back tension releases because of how they help with overcoming target panic, others strictly use them for range hunting for safety reasons.
Because there’s a surprise release and the shooter has less direct control over the release, some hunters choose to avoid these releases in uncontrolled environments. The choice is yours but be sure to take the appropriate safety precautions.
If you want to dig more into the question of What is the Best Compound Bow Release, check out this article we wrote to settle it once and for all!
There are a few methods of securing your release to your wrist. You can use a buckle strap, a Velcro hook and loop, or no strap at all. Which you choose will depend on how concerned you are with consistency and how worried you are about losing your new release aid.
A buckle strap gives you the most consistency possible. Because you need to place the buckle through a premade hole, you can be certain that the strap is secured exactly the same every time you shoot.
Additionally, buckle straps are quiet. You won’t need to worry about scaring off potential game when you adjust the strap.
A Velcro hook and loop strap has the advantage of being infinitely adjustable. They may not be as precise and can be quite loud when adjusting. However, because they adjust more precisely, they’re likely to last longer.
As the straps age, they stretch and wear. If you have a buckle strap you may simply have to deal with a slightly longer overall strap length. A Velcro strap allows you to adjust for changes in strap length over time or when wet.
Straps help shooters pull the draw weight more comfortably as the tension is spread throughout their arm rather than just on their fingers and hand muscles. However, strapless releases are becoming more popular. Strapless releases help to increase consistency because the release is held only in the hand without any length to the wrist.
Strapless releases can be hung from the D-loop allowing the hunter’s hands free to maneuver and climb. Once the hunter is set up in their deer stand, the release is already set up and ready to go, without any additional clipping required. The disadvantage here is that the release can be more easily lost or knocked from the bow.
The last element of a release aid to consider is the connector or adjustment system. If you’re using a strap, it is absolutely essential that you use an adjustable connector.
An adjustable connector will allow you to set the correct distance between your fingers and the strap. It’s important that your fingers curl all the way around the release to give you the most control. Connectors can be either solid swivel or nylon strap.
Solid swivel connectors can be purchased with a certain number of holes for adjustability. These connectors give the archer something to hold onto while shooting. This can potentially provide additional stability to the shot. Solid swivels are more traditional and maybe more familiar for many more experienced archers.
Nylon straps give infinite adjustability and also allow for both longer and shorter lengths than most solid swivel connectors. Nylon straps are flimsy and can be tucked away for more compact storage.
The ability to tuck the strap also means that the connector can be secured out of the way while maneuvering and preparing to shoot. The added maneuverability is what makes these connectors most attractive. Nylon straps greatly reduce torque but don’t allow for the shooter to hold onto them for stability.
There are many options when it comes to release aids. Single or double caliper options may give slightly different results in terms of consistency and evenness of the release.
However, this isn’t the only option to consider when selecting a release. Style, strap, and connector are all equally or perhaps more important in finding a release that really feels comfortable, natural, and effective for you.
Considering all the elements of a release will you help you find the right one. If possible, give several different styles a try before making a firm decision. Once you’ve selected your release, it’s time to hit the range. Muscle memory is everything and no release will help your shots more than hours of practice will.
I live in Alberta, Canada where I enjoy indoor and 3D archery with traditional bows and compound bows. On this site, I share everything I’ve learned about archery along the way.