If you’re new to archery, then although you’ve heard of a plunger, you might not have heard of it in this form.
The archer’s plunger, sometimes known as a cushion plunger, is a small piece of equipment that looks like a spark plug, but is essential for a consistent shot.
All Olympic archers need a plunger, as they help to set the center shot and absorb the flex of the arrow. Some barebow archers also use a plunger (or depending on the bow, shoot off a shelf).
A correctly set plunger uses a combination of tip and spring to compensate for minor adjustments in tension and release.
A plunger might not save a bad shot, but it can help you to shoot consistently.
In this guide, we’ll cover what a plunger is, how it works, and why this small piece of equipment is so important to the recurve bow.
What Is A Plunger?
The plunger is a small tool for a recurve bow that improves accuracy and bow tuning.
Also known as a cushion plunger or a cushion button, the plunger is a small cylinder that holds a spring.
The plunger is threaded into the bow’s riser, and sits above the arrow rest.
When the arrow is released, the plunger absorbs the flex, making for a straighter and more accurate shot.
A plunger is important because it reduces the natural flex of the arrow.
Why Do Arrows Flex?
A plunger is a necessary feature of a recurve bow because of the flex of the arrow.
But to understand why it’s needed, you have to know why arrows flex.
An arrow is designed to flex, to accommodate the kinetic energy that is transferred to the shaft when the string is released.
The energy is quickly transferred to the back of the bow, but it takes longer to get to the front. This causes the bow to bend from front to back.
When shooting a recurve bow, there’s another factor that causes the arrow to flex.
Because the recurve bow uses the hand to draw and release the string, there is a sliding movement across the fingers.
The string can’t be released fast enough to return to the rest position in a completely straight line.
The movement of the string is transferred to the arrow, causing some bend and flex.
Along the shaft of the arrow are two node points, and it’s along these nodes that the arrow bends.
The line that can be drawn between these nodes is the path the arrow takes.
By using the plunger, you can adjust the line between the nodes, and reduce the amount of flex all arrows have.
How Does A Plunger Work?
There are two key components to the plunger: the tip, and the spring. These work together to allow you to compensate for the arrow flex.
The tip of the plunger goes through the bow riser, and it can be adjusted.
The tip can be extended or shortened across the lateral plane, so that when the arrow sits in the rest, the lateral position can be adjusted.
The arrow will sit against the tip of the plunger, rather than the side of the riser.
If you press down on the tip of the plunger, you’ll notice that it has a spring.
This spring acts as a cushion or shock absorber, reducing the amount of flex from the arrow.
When the bowstring is released, the arrow presses against the tip, which depresses the spring.
The spring is then able to absorb some of the additional energy, reducing the flex, and creating a more accurate shot.
The spring can be adjusted, often by the use of a dial, and it’s important to get the tension just right.
A stiff plunger is necessary for an arrow with a weaker spine, while a stiff arrow will need a weaker plunger.
This adjustment can help to fine-tune the arrow flight, and some plungers come with multiple springs for an even more precise tension.
After the initial tuning, an archer may need to play around with the tension, to get it just right.
Why Is A Plunger Necessary?
The plunger is necessary because it allows you to set the center shot, and reduce the flex of the arrow.
Both of these features allow for a better, more accurate shot when using a recurve bow.
The center shot is the lateral position of the arrow on the bow.
When the arrow is released from the center, it should follow the center line from the bow to the target.
The center shot isn’t necessarily just the midpoint of the bow. With the adjustable plunger tip, the arrow can be moved left and right.
This means that when it sits on the arrow rest, it is lined up with the center.
To do this, the set screw is loosened, and the adjustment collar is moved until the plunger tip sits in the right place.
For an accurate center line, an archer may require the use of a tool such as the Beiter limb line gauge.
Alternatively, beginners will often be instructed on finding the center shot by a coach.
The next function of the plunger is compensating for the flex of the arrow.
We’ve covered why arrows flex, and how the release of the string can affect the movement of the bow. This is an inevitable issue.
No archer is a machine, and even the most talented won’t have a completely consistent release.
Differences in the draw and in the release will result in different energies being transferred into the arrow.
But with a plunger, these differences can be reduced.
With the tension in the plunger set, the spring can absorb levels of flex and energy from the arrow.
The minor differences of a consistent release will be compensated for, and the shot will be more accurate, time after time.
Do I Need A Plunger?
If you’re shooting an Olympic recurve bow, you do need a plunger.
A plunger will help to fine-tune a shot by setting the center line and absorbing excess flex.
The plunger can compensate for small adjustments and differences in shots, allowing for better consistency.
And a good plunger can offer repeatable adjustments, lasting for years.
Of course, a good plunger won’t make someone a good archer — it can’t ensure that you always hit the target.
A plunger can only negate small errors, and it won’t save a bad shot. What the plunger does is improve consistency.
But in order to do this, the plunger needs to be tuned right. A poorly tuned plunger can be worse than no plunger at all.
For almost every archer, even a low-quality plunger is better than shooting without a plunger.
With the plunger, you can work on your technique, and hone your skill.
The plunger is small and often overlooked, but it plays a vital role in ensuring a consistent shot.
If you’re shooting a recurve bow without mechanical aid, a plunger is important as it can compensate for the small differences in tension and release that all archers experience.
By setting the center line and absorbing some of the arrow’s flex, a properly tuned plunger can send your arrow straight.
With the help of good form and technique, of course.