In the last 6 months I've seen this several times. It is always VV powder. So far, have seen this happen with N140, N160, N165. In my own case, it was N160. Switched back to trusty H4831, problem solved.
Had a friend switch to a magnum primer and that helped. He solved the problem for good with H4350
It's hard to beat H4895 or Varget for a 308 WIN.
Had a friend switch to a magnum primer and that helped. He solved the problem for good with H4350

It's hard to beat H4895 or Varget for a 308 WIN.