Sinclair mandrel die guide/insert

thingiverse

When using the Sinclair expander mandrel with .223 Remington the case can hit the mandrel pin or go up the side of the pin which damages the case. This insert is a press fit inside the Sinclair mandrel die body and aligns the case with the mandrel. Works with other similar size cases. Aligns 300 AAC blackout cases but the Sinclair die body is too long for proper engagement, works well if die body is shortened by 5mm in a lathe. Is not easily removed so only use if you don't want to use the Sinclair mandrel die body for other larger calibres.