For us do-it-yourselfers, Midway shows 9mm Winchester Magnum brass on clearance -
Starline Reloading Brass 9mm Winchester Magnum
http://www.midwayusa.com/product/941...chester-magnum
$19.52/100 [clearance]
It can be shortened and formed in ordinary RCBS 30 Mauser or 30 Luger reloading dies.
Lots of times, 30 Luger/30 Mauser brass is sold out. This is a good source for 'field expedient' brass for these calibers (and 7.62 Tokarev as well).
(I noticed this while looking for sources of 9x25 for an export C96 Mauser.)
(Can also be used to make 9x21 IMI brass).