[Yellowstone]

After the ban, newly manufactured magazines were marked for restriction law enforcement/military only, OWTTE. Although there were so many magazines made in advance (pre-ban) there never was a shortage... just higher prices.

So, if the magazine is not marked for law enforcement/military restriction, it was manufactured pre-ban unless, of course, the magazine was manufactured after the ban ended. In that case it may also be "unmarked".

In WA most never ran out of high capacity magazines. After the ban sunsetted, we could possess law enforcement/military restriction magazines also. Your state of MA may differ.

As example, I still have new, in wrapper, military surplus AR15 magazines that I've had since before the ban. They look just like the surplus mags that were made after the ban... without the "restriction" language on them.

So, unless your source can assure you it is a pre-ban magazine you (or anyone else) may never be certain... unless it is marked with the "restriction" language or date stamped on the bottom plate. The manufacturing dates may also be found on the wrapper.

If MA has a law allowing only pre-ban magazines, I wonder how anyone could tell them apart. Besides, there are lots of lightly used Circle K magazines available real cheap.

What is confusing to me is that it appears that you are telling me that MA never sunsetted the federal 1994 gun control act, like what happened in my state. That would indeed make it very confusing as to whether you are in compliance.

I feel your pain.