Mike/Maagitas, thank you for the feedback.
I tried some 5 Remington rounds loads from my partner (generic 308) and ~15 rounds of Radgreen British surplus, all of these fed well, bolt carrier picked up the rounds from the magazine.
I may have found the issue, the Radgreen OAL is 2.785; projectile weight is 147. Chrono at 2715 Average SD 21
My loads are 2.815 OAL; SMK 155 Gr, 44 Gr Varget. chrono at 2675, SD 25, LC brass. Tried to reduce the "jump". 308 Gas guns are "interesting"
Weapon started as a Remington R25, modified to: M110 Krieger barrel, Armalite gas tube (required with M110), Superlative adjustable gas tube. Magazines PMAG & DPMS Gas block is adjusted to lock open with an empty chamber + 2 more "clicks"
Not using a small base die, my challenge is picking up round from magazine. Loaded rounds were inspected using a Lyman Case Gage. Dies are Forster Benchrest.
Bolt and carrier are lubricated, not "soaked"
My theory is that my reloads are dragging in the magazine, bolt returning into battery without picking up the round. Adjusting the gas did not (would not) address this failure mode.