Ozzistraightshooter Carbide long chucking reamer.
5.5mm diameter x 300mm long reamer.
 
Carbide flutes for cutting hard metal.
300mm length allows you to ream out muzzle breaks, long holes, etc.
Ground shank clamps precisely in collet chucks. 
A collet chuck is recommended to hold this tool in the lathe, (not supplied).
 
This is a top quality tool designed for professional use.