When I recently cast some .457 Lee conicals (.457-405 mold & .457-340 mold) I wanted to size them to .451. First off, I tried to size them straight to .451 with the Lee sizing kit, but found my light weight Lee press was not up to the job. I have one of those old Lee sizing dies in .452 that you use with a hammer, rather than a press (I don't think they make these any more). After tappingthe bullets through the .452 die, I was able to size them again to .451. If you've resized these bullets to .451, were you able to do it in one step?

Another problem I had was that I tried to use olive oil as a sizing lubricant. It worked fine in the .452 hammer die, but just would not work with the .451 press operated die. The bullet would go about half way into the die and stick fast. I didn't have any real bullet lube on hand, but did have a tube of Lee's water soulable Resizing Lubricant, which is made for sizing brass cartridge cases.I tried that and it worked OK, but still took a pretty hard push on the press to go from .452 to .451.