Accuracy is highly dependent on consistency.


Use fresh bullets and the hardeness will not have transitioned to harder or softer conditions depending on the length of time since casting and depending on the alloy used.

Use fresh bullets and the lube will not have hardened or oxidized over time; making it a better lubricant with the right viscosity to help mix and clean out fouling.

I have seen old bullets where the lube falls off in big chunks and it is obvious it will not be as effective at lubricating or have the viscosity to pick up and mix with the barrel fouling.

I use six month old bullets that have stabilized in hardness over time (minimum 90 days) but  if lubed have been stored in a freezer so the lube is fresh when they thaw out.

I believe in aged bullets and new fresh lube.
However freshly lubed and recently poured bullets will have the same consistent state as well.

But the hardness will change over 90 days and varies since time poured.
Softer for lead:tin alloys and harder for alloys with antimony.