So, close but still had to fix the .45 Colt die. The bottom ring is ok, sizes Starline fired brass (.480"+ if the New Vaquero has fired it) down to .475-6" on the body. The neck, however, was sizing the outside to .467" and about .447" on the ID. Even my Lee carbide die only sizes the neck to .470".
So an hour later, working with diamond abrasive, a split dowel, and emery paper, I got the top ring polished to where it's sizing necks about .471" on the OD, which leaves me 2.5 thousandths interference fit with a .452" bullet and obviously a bit more with a .4525" which is what I shoot uncoated. At LAST, problem solved..
Oh, and I can definitely confirm other's complaints that these dies come pre-rusted in the space between the carbide rings, which will cause scratched cases. Also, the Titanium Carbide rings themselves seem to have tiny burrs on them, so a quick polish with some very fine emery cloth and a split dowel is in order even if you don't cut the top ring .003" larger.
The .45 ACP is next, but I don't anticipate having to modify it other than a polish due to me using .4515" powder coated bullets exclusively and that's pretty close to jacketed size. Why did I get a .45 ACP die also you ask? Because most of the chambers I have are tapered pretty severely and loose in the back, and my RCBS and LEE carbide dies both size the area in front of the rim so small the cartridges literally rattle in the chambers.