Posted by L.E. Wilson INC. on 5/28/2025 to
Reloading Tools
Setting your decapping pin depth correctly is one of the simplest yet most important adjustments you’ll make at your reloading bench. Whether you're using a neck sizing die, full-length sizing die, or a dedicated decapping die, the position of the decapping pin directly affects primer removal, pin longevity, and die performance.
Let’s walk through how far the decapping pin should stick out, how to measure and adjust it, and what to watch out for.
What Is a Decapping Pin and What Does It Do?
The decapping pin (or deprimer pin) is the thin, hardened steel rod protruding from the center of a resizing or decapping die. Its job is to punch out the spent primer from a fired cartridge case as the case is pushed into the die.
If the pin is set too short, it may fail to remove the primer. If it’s too long, you risk:
- Bending or breaking the pin
- Misalignment in the press
- Damaging the case or die
Ideal Decapping Pin Depth
How Far Should It Stick Out?
As a general rule, the decapping pin should extend about:
1/8 inch (0.125”) to 3/16 inch (0.1875”) past the bottom of the die
This is enough to ensure the pin fully punches through the primer pocket but not so much that it risks damage during setup or resizing.
Fine-Tuning for Your Brass
Different calibers, primer pocket depths, and die manufacturers may require slight adjustments. For example:
- Military brass with crimped primers may need a little more stroke
- Shorter primer pockets (like in some pistol brass) may require a shallower pin extension
How to Adjust Decapping Pin Depth
Most sizing and decapping dies (including L.E. Wilson’s) use a collet or set screw at the top of the die to secure the decapping rod.
Steps to Adjust:
- Loosen the decapping rod lock nut or set screw at the top of the die.
- Slide the pin down until it extends about 1/8"–3/16" past the bottom.
- Tighten the lock nut securely.
- Test with a fired case to ensure it removes the primer without bottoming out.
Tip: Always double-check alignment using your press stroke to avoid high force on the pin tip.
Common Problems from Improper Decapping Pin Depth
| Issue | Cause |
|---|---|
| Primer not removed | Pin too short or not centered |
| Pin bends or breaks | Pin too long or case not aligned in shell holder |
| Case tilts in die | Rod not centered or not locked firmly |
| Primer cup damage | Pin strikes off-center or hits bottom of pocket |
Tools That Support Proper Decapping
To avoid pin issues and improve primer removal, pair your die setup with other L.E. Wilson precision tools:
- Punch and Base Sets: For manually knocking out primers from stubborn or crimped cases
- Stainless Neck Sizing Dies: Uses a precision-machined decapping system and will also size your case neck only with our interchangeable bushings
- Stainless Steel Neck Die Decapping Base: Ensures alignment during neck sizing and decapping, and provides a cavity for primers to collect and clearance for the sized cases to be pushed out of the die.
Final Thoughts on Decapping Pin Setup
Understanding and adjusting your decapping pin depth is critical for clean, safe, and consistent primer removal. Always start with the manufacturer’s specs, measure your pin extension, and test with real brass. A properly set decapping pin keeps your workflow smooth and protects your dies and press from costly damage.
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