Our Swage Rod Backer/Case Mouth Expander is made from D-2 tool steel, then through hardened, not case hardened, to Rockwell 58-60C for maximum life.
Expands case mouth to ~0.361"
Bullets tested below sit squarely, and have a "suction pop" sound when pulled out by hand.
THIS IS NOT A SWAGE BACKING ROD. This is ONLY intended for case mouth expansion.
Tested with 9mm (0.357"/0.358") projectiles from:
Speer Lead Wad Cutters
Required but not included:
Dillon Swage Backup Die Body p/n 12184
Dillon 9/16x18 Lock nut p/n 13483