I can't answer your question but given market trends I would guess you're going to be reloading for those cartridges or going to a boutique ammunition loading company.
There is an outfit in LaGrande Oregon developing loads for hunters if that might help you out.
Welcome to the forum.
I load for the .375 Taylor and I've found the easiest way to make brass for that cartridge is run .458 Win. Mag. brass through the .375 Taylor FL die and load at full power. Give the reformed cases just a light touch with the case trimmer to square the necks.
I think you could do the same to make brass for the .416 Taylor. It's a lot easier than necking up .338 Win. brass.
Paul B.
