As I was perusing thru my gun club links I found the following site that might interest you 300 Blackout loaders and shooter. I don't know if it is a good deal since I don't have that caliber and have not purchased from this company before. Just though it might come in handy for someone. Moderator if this is in the wrong place I apologize and please move it for me, Thanks.
https://www.wideners.com/itemdetail.cfm?item_id=100002073