I've heard a couple of guys mention that some of the S&W ultra-light weight revolvers like the 340, 340 PD,386 PD, etc. with Scandium frames have given problems when using stout defensive ammo. Supposedly , the built-in lock engages somehow during recoil and locks the action at what could really be an inappropriate time if you're dealing with an emergency. Can anyone VERIFY an ACTUAL occurence of this kind of thing happening and give the particulars?