kevcarron,
The short answer is NO, it doesn't work reliably in the KRB7.
This is due to the play in the breech block, not sealing the primer in the pocket well enough for good ignition.
IMO, it could be made to work using an o-ring mod, quite possibly without any further mods. I don't own one, or I would give it a go.
BH209 needs a hot primer with a good seal, to keep the heat and pressure up for instant ignition. The slop/play in the breech block is just enough to break the seal, thus hangfires and misfires are the general rule in the KRB7.
