Went to the range this am with some 129 SSTs loaded up with 8208XBR. Also shot some of my previous OCW load (AA Entry) of 129 SST driven by AA2230 for comparison.
My current rig is Satern 18" in AA upper, adjustable gas block, Vortex PST 2.5-10x44, WCI brake.
The XBR loads were 26.2 gr, 26.7 gr and 27.2 gr. The 27.2 looked most promising and I don't believe showed any high pressure signs (I could use some expertise here).
If someone can also explain the variation in groupings (vertical, horizontal spreads), I would appreciate it.
The AA2230 load was 25.5 gr and had proven to be the most accurate of the AA2230 loads I tested in my AA Entry. The velocity is too low for my liking...