Originally Posted by
Dieselhorses
First of all, if they are casting at .451 you may not even have to size, depending on what you're shooting from. Second, I have boxes of .452's for my 45 ACP that's been sitting for months, a few weeks ago I dug out 100 and powder coated. I cast from a Lee .452/230 and I don't size them simply because 99% of them just slide through sizing die with no effort at all. Thirdly, never size a bullet with no lube or powder coat as you'll lead up you die. Surefire way to get an accurate measurement is to slug your barrel. Measure the "groove" (highest) part around bullet.