As of Jan 2012 the 442 Pro series (Uses Moon clips) is a new manufacture that is WITH OUT the internal lock
https://www.usconcealedcarry.com/rev...-with-a-twist/
EDIT - another 10 seconds and I could have said... a non moon clip version also.. just a little searching on the S&W site.
442
http://www.smith-wesson.com/webapp/w...layErrorView_Y
642
http://www.smith-wesson.com/webapp/w...layErrorView_Y
Hope it helps