PF stands for Push Feed action.. If you have an "E" now, then by all means obtain another "E".. He's right about the DBM being run only a few years, 92-94 (according to the Blue Book.
They weren't very popular and Winchester discontinued them. I'm guessing that "E" box was used for the DBM due literally to it's size.. It would allow the insertion/removal of a detachable box. However, it's use was really for rounds as I noted above..
But now my question is - are you just trying to add another "E" box or are you trying to find another detachable magazine? According to your chart you note in the original post, the "E" box is for the push-feed (PF) action.. But you indicated you have a Classic rifle, ergo, that would mean you'd need the "EC" magazine..
I don't show those - at all - in any of my parts books..
Interesting.
