I cast and loaded some DERS bullets that had been quenched in ice water, optimistic that they would reach my goal of 45 BHN. As it turned out, they were no harder than bullets quenched in room temperature water. Nonetheless, since they were already loaded I might as well shoot them.
The weather has been cold and stormy lately. I waited for what appeared to be a calm morning. It was 40 degrees F outside but 60 - 65 F inside the shack. At first it was calm, but by group #5 the wind had kicked in. It was only 5 - 10 mph, but it changed direction several times a second, making wind doping nearly impossible. In hindsight I should not have attempted to shoot today, but you can't be sure until you try it, and there was no better weather in the forecast, and winter is knocking at the door.
The usual procedure of cleaning every 10 shots, then firing one fouling shot off the target.
Bullets were seated 2.699", which is approximately "jam minus 10."
The ice water quenched DERS alloy measured 40.3 BHN today after aging for 2 weeks -- that's not significantly different than the 39 BHN of the J.R. brand reclaimed shot used as a control load, so I did not expect a significant improvement in accuracy.
The DERS bullets averaged 0.89", worse than the control load.
"Clean" groups averaged 0.88" while "Dirty" groups averaged 0.90", not a significant difference.
Groups #1 - #5, shot under calm conditions, averaged 0.79" while groups #6 - #10, shot under windy conditions, averaged 0.99".
The 0.79" figure is more representative of what the DERS bullet can do under good range conditions, yet it is still less accurate than the control load, so the 40.3 BHN DERS bullet was actually less accurate than the 39 BHN control load.
OK, so the ice water quenched DERS alloy was a failure in the sense that it was only 2 BHN harder than ordinary reclaimed shot at a given age. But that trivial difference in BHN does not explain why they were less accurate than the control bullets, does it?
Besides the tiny difference in BHN, there was also a difference in density and a difference in diameter. The DERS bullets weighed 199.5 gr. vs. 202+ grains for the control bullets. You wouldn't think that would be significant, but it can change the bullet's dynamic balance, so that's one possible explanation for the poor accuracy.
The DERS bullets dropped out of the mold a little fatter than the control alloy. They received the same sizing procedures as the control alloy, however the bore riding bands do not get sized, so perhaps that is a factor? I have never done any optimization experiments for the diameter of the bore riding bands on Loverider bullets, so that may be the next thing to test.
That concludes the alloy shootout. Ordinary reclaimed shot with hard gas checks performed the best.
It's looking like my part of the country may have another hard winter. If that's the case then I may not get much more serious rifle shooting done until spring. When range conditions allow I'll try to do a test with different bore riding band diameters. Should the bore riding bands be a slip fit, or should they engrave slightly?