I just got a 5906 and I have a question about the butt of the magazine clip. Could someone post a picture of a correct magazine butt end? It looks as if the end of the magazine should cover the entire bottom of the grip. Right or wrong? What is a good source for a correct magazine for the model 5906? Thanks for your help.

The 5906 magazine baseplate is pretty slim:

If by correct you mean OEM, you can get S & W 10- and 15-round magazines from just about every online vendor including the manufacturer's own e-store. I would personally recommend CDNN for significantly lower prices than S & W. They also run regular specials and often advertise reduced shipping charges as well. I'd also suggest the 17-round mags from Mec Gar. They're cheaper than the factory mags, just as reliable and give you a couple extra rounds in a flush fit design.

The baseplate on 15-round factory magazines is the same width as the width of the magazine and it does not cover the width of the butt of the gun.

The baseplate on 17-round Mec-Gar magazines is wider than the width of the magazine and covers nearly the entire width of the butt of the gun.