Expander Mandrel Set

The APW Expander Mandrel effectively smooths and gently expands the case neck, ensuring consistent neck tension. This method has proven to be the most straightforward approach to significantly reduce Extreme Spread (ES) and Standard Deviation (SD) figures.

Commercial die manufacturers often lack standardized specifications for the expander ball in their dies. This variance necessitates proper inside diameter sizing before seating. We recommend the complete removal of the expander ball from your resizing dies.

Your final step before powder addition should be to expand your necks using the appropriate expander mandrel. When employing the mandrels, we advise using Imperial sizing lube sparingly, as a little goes a long way. We employ a single-stage press to expand the neck on the downstroke, followed by packing the brass, now “ready for primer and powder,” into our APW reloading trays.

The die body is compatible with your standard reloading press, and the interchangeable mandrels are precisely sized. The kit comprises mandrels for achieving 0.001 or 0.002 neck tension, along with a base to maintain organization when not in use.