UPDATE
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Now that the holidays are behind us, I got a chance to try out some Herco loads yesterday with the 185 grain Gold Dots. I did pick up a brick of magnum primers for future use, but these loads were still using standard primers...
Started at 8.5 grains Herco and worked up in .5 grain steps to 10.0 grains. The lighter loads had some unburned residue left in the barrel, moderate sooting on the outside of the cases, and somewhat erratic velocities. All three conditions improved steadily with increasing powder charges. At 10.0 grains, the spread was pretty small (don't have my notes in front of me) and the velocity averaged out right at 1,400 fps. Herco is a pretty bulky powder and there's not much empty case left at 10.0 grains. It's still a long way off from the performance I got with Long Shot (I don't think another .5 grains is going to buy me 400 fps!) so it's just an academic exercise at this point.