loading 7mm whisper with 30 whisper dies

[cr500]

I am ordering a barrel for 300 whisper soon, but I also have a spare fast twist 7mm barrel which I dont have any other use for. I was wondering if I could use my 300 whisper dies to load the 7mm whisper? Does anyone make 300 whisper dies with removable necksize buttons?
Will the 30 cal seater stem still grip the 7mm bullet? Who has tried this?

[Spook]

I would be thinking 7MM TCU, dies are really easy to come by.