Not just there frames, parts are cast as well. I am not a metallurgist and don't know the particulars of Rugers cast parts or S&W MIM parts in my book cast is cast and I prefer a solid forged part. but I don't think there is a high failure rate for cast/MIM parts if there is I haven't heard of it. The parts are so precise you don't need to fit each part as you did with forged parts. Problem with S&W is minor things that could and should be fixed such as getting barrels clocked correctly, knocking the high/sharp areas off of the cast parts. A little quality control would help a bunch but of course you only here about the problems nobody says a word when there gun is perfect.