Hornady has redesigned their 500gr RN softpoint to an Interbond (bonded core) rather than the old style Interlock. Perhaps the 350gr RN is being cleared out for the same transition? I've not heard this, but am guessing as that is why the 500gr RN Hornady has been out of stock at dealers for at least 8 months or more. I just got a shipment sent out of the new 500gr Interbond.... It may arrive today I'm hoping! Will let you know how they do when I get a chance to try them.
The bonded core design is generally superior and this is an excellent idea on the part of Hornady. Dare we hope for the 350gr JFP for the lever guns to go to an Interbond also???