Forster Products are now making reloading dies for the .300 AAC BLK.

Full Length Sizing Die only, 300 BLK, Part # 005545
Standard Seating Die only, 300 BLK, Part #006205
Ultra Micrometer Seating Die only, 300 BLK, Part #U00099

Set of Full Length Sizing Die and Standard Seating Die, 300 BLK, Part #004453
Set of Full Length Sizing Die and Ultra Micrometer Seating Die, 300 BLK, Part #U04453

[ Many thanks to Robert for emailing me the info. ]