I had a great phone call with the folks at CH4D yesterday, and to my surprise, they can and will be sending me a complete set of dies for this cartridge. I'm so pleased by this, as I fully expected to be told they weren't willing to make a set, given how uncommon the 2 7/8" version of the 450/400 is. Those dies will actually arrive before the set of 500/450 No1 Express dies I also ordered for my Tranter single shot.