Lee Loader

Unless things have changed, using traditional lee bullet lubricating and sizing die kits, you will soon realize that sizing dies have a limited number of diameters available. being cylindrical parts rather simple to produce industrially, but a little laborious to expand with precision, it would be a significant commercial improvement to expand their inner gauge range, and a big service to casters, too_

Then folks like Ammohead over on Castboolits forum and formerly Buckshot would be out of a retirement hobby job .

NOE makes a bushing style sizer . The die is about $25 for the first piece then bushings are $12-15 each after that . If memory serves they are standard cal -002 up to to +.007 . So 35/38, 9.3 ,375 has bushings from .354-.380 and 30/31 8mm cal goes from like .302-.330 in mostly .001 steps there is a gap between.288 & .302 . It's not Lee of course but it is in the type .
Ammohead aka Bruce Forchett also makes H&I dies reasonably priced as well as the push through type . I have 2 of his and 4-5 of Buckshots.
Those and 6-7 Lee's and 9 or so H&I for Lubesizers cover almost everything I need for 17 cal with little delights like a 6.5 that needs a .272 and a 7.7 and 7.62 that need .3165 .

Logistics plays havoc here , there's 2 blocks of calibers that can easily want for 25 diameters when you start looking at 7.35-8mm as one group . Then you have 9× and 35/38s 22-24 more there .
Add in under size for paper patch cores and now there's.298 to .329 and .351to .368 which is now into the .375s like 38-55 and H&H so it's more like .351-381 . That's 60 dies and we aren't even into the train wreck that resides between 243 Win and 7×57 . really with the above it's almost a solid block from .237 to .287 ........ there's another 50 . At least the 45/11mm only wants for .448-.463 , only 15 more .

I think this is an area where the boutique guys could take about all the pie they can eat and the big boys are money ahead to let them have it .

And that's just the beginning. You would first have to have a mold that would drop bullets to an as cast size that could be sized down to a "overbore" rifle or cyl. bore size in a particular caliber handgun.

Fortunately my Lee moulds drop a little fat anyway . Actually I think I only have one that's small and it's not one of the usual suspects .