Finally got around to this, well sort of anyway.
Threw 10 loads of 27.5 Lvr, 105 HPBT in range pick up Hornady brass.
2 to line up and then 8-shot group. I think it'll be a shooter.
Only ejected the last 2 rounds, and they didn't go far...
Bolt locked open on empty mag every time, brass laying (backwards 3x) in the upper on top of mag. Never had any issues with the 6.5 barrel and bolt. Only other change was going from mid-length to rifle gas. Rifle ejected dummies fine. Only thing noticeable on the cases were pretty deep grooves/marks from the extractor.
I'm still horribly uncomfortable shooting these. Just doesn't feel 'right' at all. Need to work up to pressure in these virgin Starline cases and load the lot and practice more. Was really surprised the group wasn't quite a bit bigger, felt like I pulled most of them.