Drake:
I had the same thing with my South African Police MKIV, rounds would hit point of aim with the old dominion ammo and around 3 inches low with Winchester LRN.
I shot off what was probably the last box of Dominion .380 Revolver in Australia and only managed to find 2 boxes of Winchester in 12 months at $55 a box. So I've put it on consignment and gone back to S&Ws in more common calibers.
Interesting comment about IIz being a smokeless military round, the Australian issue 9mm para round is MK2z. The more things change the more they stay the same.
PMJR:
Sorry for hijacking your thread. At the moment I'm not aware of any .380 ACP capable revolver other than the Medusa and they are scarce as hen's teeth.
If you haunt the various auction sites you will find the occasional 9mm parabellum revolver for sale, such as the S&W 547. There is one for sale here:
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=149043148
Others to look for are the Taurus 905. S&W 940, Ruger SP101 and Ruger blackhawk convertible. Apparently the Taurus would shoot .380 ACP using moon clips, but the moon clips are rather poor quality and new ones may not be available.
Just expect to pay through the nose for one due to the small number available as they are all discontinued in 9mm.
Or you can wait for the Charter rimless revolver. At the moment it's vapourware however, as the original announcement was for availability in the first quarter 2009, now it's 'early 2010'. Charter Arms has gone broke and been revived a couple of times, and their reputation for quality has always been variable. I personally would wait till a gunshop has one in stock and inspect it thoroughly, rather than ordering one in.