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I heat treated some PC'd gas check installed 260gr 44 mag bullets at 425F for one hour, water quenched and the copper checks turned a solid brass color. My convection toaster type oven does not have any identifiable hot spots (in the past I had positioned thermocouples at many locations looking for them).
So I must assume I have fully annealed the installed gas checks. Can I expect any issues or is this just a 'whatever' thing?
You need to get Copper up around 750-800 degrees to anneal it, yours just got hot enough to tarnish.
I wouldn't worry about it either way.
Question, why the water quench after heat treatment?
The heat treatment and the following quench is what increases hardness. No quench equals air cooled which the boolits are already with a 11-12 BHN. My heat treatment/quench got me up to 15 BHN with pencils. They are below the chart predictions from the provided link, but fine for my purposes.Quote:
Originally Posted by 30calflash
http://www.lasc.us/HeatTreat.htm
I understand that, I re read the op's post and thought he was heat treating gas checks, not bullets with checks. My bad.Quote:
Originally Posted by oley55
I have read of folks heat treating gas checks to eliminate the springiness of them, resulting in a check slightly larger than a sized bullet. After treatment the checks are softer and stay closer to the sized diameter of the bullet size.
What I've understood is to heat treat the bullet first then apply the check as in some instances the check will cause the base section of bullet/check attachment to separate during the heat treat.
30calflash, I think I have read one of the issues of Heat treating the gas checked bullet is that the copper is a good conductor of heat and can result in the shank of the bullet exceeding the melt temperature of lead. This can result in the partial collapse of the cast bullet at that point.
I do not recall if I read that in the Handloader collection of articles, or Cast Bullets by E H Harrison. I have never tried it, but just HT the casting and then seat the check to avoid working the casting in the sizing die.
Heat treating a cast bullet for harness increase post-casting (sounds odd writing it, I mean to communicate as in using an oven and not water dropping while casting) is done by bringing the bullet up to a relatively high temperature (just short of slumping, or deforming) and then quenching in cold water.
This mimics dropping a bullet that has just solidified in the mold into a water bucket, but can be better controlled in regard to temperature.
Under these conditions, the bullet metal is very soft. I don't think the heat conductivity of the GC has much to do w/ causing issues at the bullet base. It is much more likely that the residual compressive stress needed to crimp the GC would cause the bullet issue described in post #6 because the bullet material is very soft at the point prior to quenching during a heat treat process like this.
Didn't your PC burnup?Quote:
Originally Posted by oley55
If you are PCing after heat treat, then are you water quenching again?
If not, you are annealing the lead alloy, so it's soft again, like air cooled alloy.
Water quench your boolits if you want. Fit gas checks to them and you are good to go.
Quote:
Quote Originally Posted by oley55 View Post
I heat treated some PC'd gas check installed 260gr 44 mag bullets at 425F for one hour,
...SNIP
Since the order of operation and what I did is unclear, I'll try the longer version.Quote:
Originally Posted by JonB_in_Glencoe
I had Beagled a mold to get (up to/close to) .434" boolits. The GC shank became larger and seating GCs' was difficult. The option of PCing and then installing checks would have required expanding the checks. So I installed the checks, PC'd and sized. Then I heat treated/water quenched. So the question was; did the heat treating at 425F for 60 minutes anneal the copper gas checks. Responses indicate, the copper now brass colored gas checks are not annealed.
As for, did I burn up my PC? Answer is No. There is a thread running now asking about over cooking PC and what I did does not/did not harm the PC. No discoloration and hammer smash/squish show no issues. https://castboolits.gunloads.com/sho...le-to-overbake
I only asked, because I would have thought heating the PC a second time to 425 for an hour, would have made the PC crispy. I guess my assumption is wrong.