October 29th, 2015

K&M Ported Expander Mandrel Window Riser

K&M Expander Riser

K&M Precision Shooting Products has a very handy tool few hand-loaders know about. This brilliantly simple device lets you actually SEE your case necks as you expand them. This tool can benefit anyone who necks-up brass or who uses an expander to smooth out necks (or reduce tension) before loading.

K&M Expand Mandrel Window Riser
This is a simple threaded extension placed between your expander die body (K&M Expand Iron) and the top of your press. It carries the expander mandrel higher, above the press, and has a cut-out view port so you can see the mandrel as it passes through the neck. Smart, eh? This provides visual feedback during the process of expanding your brass. The patent-pending view riser costs $20.00. Will it expand necks faster, or reduce run-out? We doubt it, but we still would like to have one, if only to eyeball the mandrel to control the neck-entry rate more consistently from case to case.

Installation: Thread the Expand Mandrel Window Riser into the top of your loading press, then thread the K&M Expand-Iron (Expander Die Body) fully into the top of the window riser and adjust each so you can stroke out the press completely without driving the case mouth into the press adapter. This allows you to view the expanding operation which is typically blind under the press. The riser also eliminates the need for the stop screw in the expander mandrel. LINK: Expand Window Riser Instructions (PDF).