John,

The 20 has a 30 degree shoulder so just bumping it back won't work. I already thought about the bushings, but that still leaves me with doing the shoulder in a separate step.

I bought the CD4 dies. I was a little worried because of the low price ($69 compared to well over a hundred for Redding dies). I got them in and took a .223 and lubed it and one pass later I have my first .20 Tactical case.

AlanC, I don't know if you've loaded for the Tact.20 before but a caution if you haven't. Be sure when you size for fireforming there's a bit of a crush fit in the chamber with unfired brass. The pressure spike is different in small caliber hyper rounds and some dies set the shoulder back too much and create excessive headspace.