Re: .284win neck turn question
Your rig is nearly identical to the one my brother built. He and I shoot frequently, so I have shot it a ton. He runs H4831SC, Berger 180 vlds, but uses Fed. 210Ms for primers.
I have no problem with the burn rate of the powder, given how well my brothers runs. Nor do I have a problem with the neck clearance, as my custom chambers run the same 0.0015 per side. I am not a big fan of trying to seat "touching" the lands. For me its either jump them or jam them, no in-between.
Since you didn't post a picture of your fired brass, I'll go ahead and ask - did you turn the necks all the way into the shoulder? if not you have a doughnut on the back end of the neck. If you are seating down into that doughtnut, it will create problems.
+1 - once you settle on a load, then you tweak the seating depth (both in and out) to see if you can hone it even further. For me, with my .313 neck (.310 loaded rounds) 7WSM shooting BErger 180 VLDs, there is a huge accuracy change between "touching" (1+MOA) to 0.015 jammed (bugholes). My brother's .284 reacts the same.
if you've never jammed before, make sure you reduce the load and work up; its a different world.