Heat treating / water quenching

[Skelly607]

In heat treating/water quenching... ...I have heard that this process only affects the outside of the bullet and after sizing I need to reheat the bullet and water quench again. My question is......when the bullet which is larger than the bore goes down the barrel...... wouldnt this remove the outside layer of the bullet where the heat treating is supposed to be? Any comments?
Skelly
Danville Va.

[lurch]

My general understanding in general terms:

Heating a boolit up to a point a little lower than the alloy "slump" temperature and then water quenching will affect the hardness throughout, not just the surface. The hardening does not happen immediately but will take place over the next several hours to a couple of weeks depending on the temperature heated to, the cooling rate and the alloy. The degree to which the interior hardens for a given boolit would depend primarily on the rate at which heat is removed from the interior vs. the outside. Larger diameter boolits will have softer interiors than smaller diameter ones. all else being equal because the heat cannot be removed as fast from the interior as it can from the outside. In my opinion, the depth and amount of hardening for any boolit will be more than sufficient for any reasonable application under normal circumstances. When fired, the deformation of the surface of the boolit by the rifling lands and grooves will to a degree work soften the boolit surface, but not enough to worry about.

Most folks will either size a boolit and then heat treat and lube at some later convenient time or heat treat and then size/lube very soon (essentially immediately) afterwards to prevent the work softening of the outer skin of the boolit, as the hardening takes a little while to actually happen. This will result in sizing an "unhardened" slug and the surface is then free to harden.

Other opinions may vary...

[sqlbullet]

Definitions of surface vary greatly. However, for our purposes, the hardening is not just on the surface of the bullet as far as sizing and engraving of rifling are concerned. The standard indent test for measuring hardness exceed these depths.

Also, while lead does work soften, sizing or engraving don't remove all hardening immediately.

And, as lurch says, if arsenic is present, the bullets will definitely continue to harden over several days/weeks. I generally cast->quench->size as rapidly as possible.

[Greenhorn44]

FYI. When quenching the water can become rather hot. Test it with your finger before sticking your whole hand in......Just a thought