I attempted alot of research on this just a couple months ago.
The currently recognized version was adopted by Norma, so sometimes it will say Norma on the item. Sometimes just 6.5-284, but it's the same thing.
My 6.5-284 Lapua brass says 6.5-284 Norma on the box and so do the Redding dies.
Some guys may use Winchester 284 brass and actually neck it down, but once it's fired in the newly adopted chamber it becomes 6.5-284 Norma anyway.
Near as I've been able to tell or research, there is no appreciable difference in the modern version. I might be mistaken, but I think anymore its all simply 6.5-284.
Would be great if someone would post a cartridge diagram of 284 winchester vs the current version, but I haven't seen any such thing.