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Set me straight on this . Say I cast up some 35 cal rifle bullets in 50ww/50soft alloy I water dropped them as usual for this alloy mix . They are in a harder state now of course , will sizing them within say 24 hours soften the bands any ? If so how much ?
Tim
sorta.
they still have a couple of weeks to finish hardening.
and the bhn goes all the way through.
The key thing to remember, as runfiverun points out, is in a quenched bullet, the BHN basically goes all the way through. Any work softening you introduce will only be .001-.002" deep at most. Rifling is generally .004-.006" and we size .001 or .002 over. It is really not an issue.
Plus, fit is king, not hardness.
Thanks both , I kinda thought the hardness would be all the way through on smaller skinnier bullets like a 30 cal or under but wasn't sure on the fatter bullets . Did the calibrated finger nail scratch test on one and the band areas that got sized didn't feel any different than the nose .
Tim
Sizing work softens the skin by 'moving' a slight bit of alloy but aging re-hardens the boolits. Molecules move around in alloy even at room temp, WD & AC are the same but WD just freezes the crystal rapidly so 'harder' crystal structure. Think of AC as being more 'destructive' on the lattice. Most important part of the freezing occurs in the mould where we have no control. Maybe there is a 1/10% difference in BHN through the boolit but we can't measure it. Like R5R says, don't worry about it.
this is another thing I discussed with Felix at one time.
his recommendation was to leave the heat treated boolits alone and then size them just before using them.
this is something I still question.
except that I know water dropped alloys can grow in diameter over time.
[all antimonial alloys do actually]
his reasoning was the sizing just before loading and shooting would bring everything into sameness again.
now we were discussing extreme accuracy, and exactness there is necessary of course.
the slight loss of bhn was inconsequential compared to the fitment.
I try to size WD in a day or so, a few days for AC - causes less distortion of the base. Read an Army Lab test report a few years ago. Measuring the radial (outward) force from firing a bullet. My conclusion & theirs is that lead doesn't get 'sliced' into the groove but is really 'swaged' in, i.e. lead NOT in the groove gets pushed in (& work softened). Lead doesn't cut very easily, mostly it flows. Notice nose 'skid' and no body 'skid'? Not enough lead at the nose to flow fully so 'hold' in the rifling is less. Weak spots in the 'flow' break off. I add copper to my allow which makes it more resistant to that breakage.
I've never noticed any difference.
If you're concerned, you could oven heat treat and then quench your boolits after sizing them all. Then lube them with a lube die that's .001" over your boolit diameter.