Reamers
States - Manson Tools, JGS, Clymer - it’s a real shame Geoffrey Kolbe stopped making reamers in Scotland (BBT) they were really good
Barrels - some brilliant folk import Bartlein, Kreiger and Brux into the UK
Plus UK manufacturers - GB Barrels and Phoenix
Europe - Lothar Walther
Tools - Brownels (spent thousands before you couldn’t order direct)
MCS tooling , Cromwells and most quality engineering suppliers have inserts and other bits you need as expendables