BHuij
Active Member
Hey everyone--
I'm doing some testing to find what works for me to hit various targets for BHN using COWW alloy. Effectively, I'm testing different times and temperatures for heat treating and quenching bullets of various calibers, and tracking their BHN at the 0-day, 1-day, 7-day, 14-day and 60-day marks.
Later, I'll also be trying some various methods of powder coating and quenching to see if I can get higher BHNs in some of my powder coated bullets without having to play around with different alloys.
Yesterday I cast up a bunch of bullets from a number of molds, all using the same pot of 100% COWW alloy. These were allowed to air cool. Within 6 hours or so of casting the bullets, I measured the BHN on some of them, and it averaged out to about 8 BHN, softer than I was expecting for COWW. This morning (~18 hours after casting), I measured several more from the same bag and they were averaging about 9.5, which seems closer to what most people report for this alloy.
I'm aware that after heat treating/quenching, it takes bullets anywhere from several days to upwards of 2 weeks to reach their "peak" BHN, depending on arsenic content in the alloy, and some other factors. However, my results so far suggest that even air-cooled COWW bullets might take at least a day or so to get to their "actual" base BHN, maybe longer. I'll have to confirm with further testing. Has anybody else ever noticed this?
I'm doing some testing to find what works for me to hit various targets for BHN using COWW alloy. Effectively, I'm testing different times and temperatures for heat treating and quenching bullets of various calibers, and tracking their BHN at the 0-day, 1-day, 7-day, 14-day and 60-day marks.
Later, I'll also be trying some various methods of powder coating and quenching to see if I can get higher BHNs in some of my powder coated bullets without having to play around with different alloys.
Yesterday I cast up a bunch of bullets from a number of molds, all using the same pot of 100% COWW alloy. These were allowed to air cool. Within 6 hours or so of casting the bullets, I measured the BHN on some of them, and it averaged out to about 8 BHN, softer than I was expecting for COWW. This morning (~18 hours after casting), I measured several more from the same bag and they were averaging about 9.5, which seems closer to what most people report for this alloy.
I'm aware that after heat treating/quenching, it takes bullets anywhere from several days to upwards of 2 weeks to reach their "peak" BHN, depending on arsenic content in the alloy, and some other factors. However, my results so far suggest that even air-cooled COWW bullets might take at least a day or so to get to their "actual" base BHN, maybe longer. I'll have to confirm with further testing. Has anybody else ever noticed this?