it was my first time I will get better as I go along.
I haven't found the failure point yet in preliminary testing, usually I run out of pressure headroom first. 12 bhn to nearly 3kfps in the .223 and 10.4 to 2400 so far with just one try in .308. The alloy still has to be right (can't be too brittle, or too mushy with tin) but it can be a damn sight weaker than would ever work without the coating and shoot like "RPM what?"PC allows you to get away with softer alloys up to a point.
I'm betting Popper is playing closer to the 24-2700 fps zone though.
All true. I went as far as to do this with double-ended wadcutters as a litmus test, half with sprue up, and half with sprue down so I could test bullet hardness on the ends of the bullets without having the sprue cause erroneous readings. It came out this way every time unless I used my steel heat sink to keep the noses hot longer. I did not try my heat sink on pointed bullets because there was too much air space at the heat sink, and I felt that would give erratic readings. In short, the temperature travels from hot to cold, starving the hottest end of temperature first, and rather quickly. I later found this to be the second law of thermodynamics.It don't work the way you think it does.
I did a bunch of tests just like yours and the quench sucked the heat out of the noses so fast they actually got harder than the bases. What happens is the heat is sucked from the nose into the base and then into the water, and the base stays hot longer, making it in effect cool slower than the nose. Hence harder noses. The longer and more pointy the bullet, the worse the effect.
It's a good thing the Oehler 35 doesn't have temperature inputs or it would already would have happened. A name other than the "Second Law of Thermodynamics", of course, which it already has had for a couple hundred years thanks to other guys we've all heard of named Kelvin and Joule and so forth.weird that's how brass annealing works too.
you'd think some smart guy would write up some kind of physics paper and name it [insert name here]'s law.