M5 configuration generally cures all feeding woes. Which mag box and follower are you using for the BDL setup? If you aren’t using one of the windowed ultra mag boxes be it Remmy or Wyatt I’d start there.
Ended up using a LA Mag follower and and ultra mag, windowed magazine. Still had to position rounds on the follower slightly ahead of the back of the magazine. That pretty much cured the feeding issues. Still wasn't real happy with the smaller loading port on the Bighorn action, so I dropped it in a Grayboe Terrain with a Grayboe std length (3.715') M5 DBM and 300WM Accurate Mag. Absolutely NO feeding issues with the M5 DBM.
I'm already toying with the idea of building another. If I do, I'm probably going to go with a Defiance Deviant Hunter SA Mag cut for the Wyatt's extended magazine. The Wyatt's gives an extra .100" of length, and the Deviant Hunter has a much more open loading port.
