I waited 10 months for the tax stamp on my first can, 5 on the 2nd and 6 for the third. I am now enjoying what will be an even longer process as I wait for the 4 additional cans I bought in order to beat 41F. And, to add insult to injury, ATF cashes your check in 2 weeks or less.
I am waiting on my 3rd. Check was cashed in March so according to NFA Tracker, it should be any day now.