Threading barrel of a VEPR K in 7.62x39

My VEPR's barrel measures out to be .610" and I want to thread it to 14x1mm LH threads. My questions are:

1) is this diameter to large for a 14x1mm die to thread?

2) if so, what are different ways that I can grind/sand/dremel to reduce the diameter of the barrel closer to 14mm so that I can thread it?

Thanks.