FWIW, I have a small quantity of those "Primer Pocket Bushings" that some entrepeneur was spooling up and flogging in the BP classifieds,.....jeez, at LEAST 10 years ago. Good examples of what a Swiss Machine with a bar feeder can spit out, they take a standard LR pocket down to SP.
Anyone interested in playing with em' PM and I'll send em'. You'll owe me a beer,....and putting your (coherent) results here. GTC.
Greg, those bushings were a necessity back during the early days of the .454 Casull as it needed the oomph of a small rifle primer to get consistent ignition of all that H-110/W296. Eventually, they started making .454 Casull brass with a small primer pocket and thousands of the bushings became orphans.
I seated hundreds of them for my F/A .454 before switching to the small primer pocket brass.
Ed