Prvi brass... (hate S&B, primer pockets are too tight)
The 174 grain, .311 Sierra Match King. Top of the heap...
I seat mine .02 off the lands (which happens to be right at about 3.00 OAL) over 43.5 grains of Varget. Sub-moa, I haven't crono'd the load yet, but I've got 14 minutes of come-up from a 200 yard zero suggesting a MV of 2625.