The Archery Plunger Button: What It Does and How to Tune It

The plunger button — also called a pressure button or berger button — is a small spring-loaded device screwed into the riser that the arrow passes against on its way out of the bow. It looks insignificant but is in fact one of the most important tuning components in recurve target archery.

What Does a Plunger Do?

When an arrow is released, it bends slightly sideways due to the "archer's paradox" — the arrow flexing around the riser as it accelerates forward. The plunger provides gentle lateral pressure on the arrow's shaft at the point of the rest, guiding it along the intended line and damping the sideways oscillation as it exits the bow. Without a plunger (or with a poorly adjusted one), the arrow's exit path is inconsistent — one of the primary causes of horizontal grouping problems.

Plunger Components

• Spring: A replaceable internal spring (available in light, medium, and stiff tensions) determines how much lateral resistance the plunger gives to the arrow. A softer spring is more forgiving; a stiffer spring provides more precision but less forgiveness of form errors.
• Plunger body: Screws into the riser and extends to the rest position. Its depth (in or out) determines the "center shot" position — how far horizontally the arrow sits from the bow's center line.
• Tip: The tip is the contact point with the arrow. Different tip materials (nylon, teflon) provide different friction characteristics.

How to Adjust the Plunger

Spring tension: Start with a medium spring. Too soft = arrows fishtailing left-right; too stiff = arrows unable to flex consistently around the riser. After paper tuning, fine-tune spring tension to achieve a clean bullet hole.

Depth (center shot): With the arrow nocked and resting, look down the arrow from behind. Adjust the plunger depth until the arrow appears to point straight toward the target (accounting for the inherent slight offset of the recurve window). A starting position for right-handed archers: the tip of the arrow should be approximately 2–3mm to the left of the bow's string when viewed from behind.

Plunger and Paper Tuning

The plunger is the primary tool for correcting horizontal tears in paper tuning. A left tear (for right-handed archers): move the plunger out (increase center shot). A right tear: move the plunger in. Always make small adjustments (1/4 turn) and re-paper between changes.