After many years of chasing concentricity goals, I've standardized on Redding Full Length "S" bushing dies. (Yes Full Length). The only problem is, they are often out of stock, and for some cartridges, simply don't exist, even some for which there is a listing.
Looking at some standard dies and thinking (always a dangerous thing), I don't see that it would be too hard for a qualified machinist (ie, not me) to drill out the top of a typical die to accept a bushing, and thread it for a retaining plug. The new cavity would stop just at the top of the shoulder, which would be intact for sizing purposes.
Any thoughts on why this would, or wouldn't work? Anyone willing to take this on?
HF