you can have the collet turned down another 001" if necessary
I think you meant the mandrel polished down 0.001"
Also if you have not done so take the die apart. And give all the parts a good cleaning. Then use some fine grit sand paper and put the collet in and lightly smooth out the top part with the fingers(inside and out) and then the piece that the collet slides up into polish the inside of it some. Then clean again and put a light coat of lube/oil on the collet fingers