yodogsandman
Well-Known Member
Just came in from heat treating my bullets and I think I might have overcooked them.
The plan was to heat treat about a half batch (100) of NOE 360-310 FN bullets that had been sized to .360" and gas checked at 460*F or so for an hour and quickly quench them in ice water. Bullets were cast from COWW's with about 1 1/2% to 2% Sn (pewter) added. I know my temperature is off on the convection oven but, use an oven thermometer inside on the tray with the bullets to monitor the heat. In the winter the ovens temp will run 10*F over the set temperature and in summer, about 25*F over set temp. I set the temp at 450*F with a target temp of about 460*F. Didn't think that being 45*F outside isn't exactly winter temperature. So, the oven went up to 470*F and I thought it would be OK, just go back and quench them in an hour. Returned after 65 minutes and quenched them in the bucket of ice water. Swirled them around in the bottom a little with a wood stick to make sure they all cooled quickly. After a few minutes, dumped the ice water in the driveway, picked out the bullets and dried them on paper towels.
Looking at the bullets, some had what looked like scrapes on just one side of them. Just 1/8" wide and 3/4" long. Not deep, more like scratches. The bullets were discolored, too. Like they were BBQ'd. I took a couple that looked the worse and ran them in the .360" sizer again and most of the scratches came out. Now, I'm wondering if I overcooked them. I've had the discoloration before but, never any scratches. Wondering if I got so close to the slump temperature, that they scratched when I dumped them in the ice water. The bullet sides didn't show any flattening and no other signs of slumping.
I'm thinking of going back to my best load to date and trying them out. The problem there is I heat treated that batch at 430*F. So, would you guys try to just shoot them or just melt them back down and start over?
The plan was to heat treat about a half batch (100) of NOE 360-310 FN bullets that had been sized to .360" and gas checked at 460*F or so for an hour and quickly quench them in ice water. Bullets were cast from COWW's with about 1 1/2% to 2% Sn (pewter) added. I know my temperature is off on the convection oven but, use an oven thermometer inside on the tray with the bullets to monitor the heat. In the winter the ovens temp will run 10*F over the set temperature and in summer, about 25*F over set temp. I set the temp at 450*F with a target temp of about 460*F. Didn't think that being 45*F outside isn't exactly winter temperature. So, the oven went up to 470*F and I thought it would be OK, just go back and quench them in an hour. Returned after 65 minutes and quenched them in the bucket of ice water. Swirled them around in the bottom a little with a wood stick to make sure they all cooled quickly. After a few minutes, dumped the ice water in the driveway, picked out the bullets and dried them on paper towels.
Looking at the bullets, some had what looked like scrapes on just one side of them. Just 1/8" wide and 3/4" long. Not deep, more like scratches. The bullets were discolored, too. Like they were BBQ'd. I took a couple that looked the worse and ran them in the .360" sizer again and most of the scratches came out. Now, I'm wondering if I overcooked them. I've had the discoloration before but, never any scratches. Wondering if I got so close to the slump temperature, that they scratched when I dumped them in the ice water. The bullet sides didn't show any flattening and no other signs of slumping.
I'm thinking of going back to my best load to date and trying them out. The problem there is I heat treated that batch at 430*F. So, would you guys try to just shoot them or just melt them back down and start over?