I fired the .280 yesterday for the first time since I adjusted the extractor.
This barrel has been a 2 MOA (with loads it likes) since I've had it, with only Hornady 175 RN bullets and IMR 4350 giving close to 1.5 MOA.
With 154 Hornady Spire Points and RL-19, my first three shots from a clean cold barrel went into 1.2". Two more groups were 1.2" and 1.7".
I'd never tried this load before, so maybe it wasn't the extractor. This still isn't great, but I'm happier with this barrel now than before.