Probably cast them with a 1:40 alloy. If they shoot good and he doesn't want to sell me it I may just order a 45-480M mold from Accurate. If I do I'll order it with a .452" +.002 -.000 tolerance. Then I can always size it down a bit.
I just got done casting some .457" 350 gr bullets (the ones I shot in the first target) and sized them down to .451" in 2 stages. I sized to .454", lubed them then to .451".
That much sizing though takes a lot off the lube grooves.

Wow looking at your target that bullet drops 9" from 100 to 150 yards!