When I could not find a SD9VE magazine, I bought a SW9VE magazine and it fit perfectly in my SD9VE. (This was some time ago...SD9VE magazines are more available now; Greg Cote LLC has them in stock.) The magazine body and internals are identical, except for one small difference: on the SD9VE magazine, there is a small rectangular depression on the forward facing side of the tube, right below the feed lips; there is one as well on the SW9VE magazine tube, but it is slightly less defined.
The SW9VE locked into place, fed, locked the slide open, and in all respects worked just as well as the SD9VE magazine. I called S&W customer service and they sent me a SD9VE base plate, which I put on the SW9VE magazine, and other than the small depression I mentioned, it is now identical to the magazines that came in the box with the SD9VE when I bought it. The SW9VE base plate is a little different, in appearance, but it works well in the SD9VE, so I wouldn't bother to change it out again...unless you are as anal as I am. Functionally it's not necessary, and it doesn't even look bad (IMO), but since I was able to get the base plate I switched it out (since I am, as mentioned, anal.)
Since they are both available (at least on Greg Cote's site) and they are the same price, I'd buy the SD9VE magazine, but if you can only find the SW9VE magazine, or it's cheaper, it will work just fine.
..I called several internet gun & accessory sites and got the same story from all of them SD, SD-VE, or SIGMA 16 round magazines are out of stock and they don't know when they'll get anymore.
