There are tools to measure wire gauge with, or you can just mic it and look it up on the chart.. (Thanks for the heads up I'll start doing that myself)
IF you get 12 ga that is really 13 or 14, take it back, And report it.
This is where far too many people fall down on the job.. They make a post in a forum somewhere.. What you need to do is notify the safety folks, they have teeth, this forum,, Well one slightly decayed tooth. (by comparison that is.
If the regulatory folks measure 100 or 1,000 samples of wire from that company and they all test "Light".... I would not want to be them.
