Freedom Arms, Dan Wesson, Les Baer, Ed Brown, Wilson Combat and I'm sure many others.
I'm pretty sure I have seen where Wilson offers several levels of quality in their parts. Some are machined from "bar stock", some are MIM, etc.
Some have also been known to compromise the use of the term "bar stock".
Dan Wesson had a problem with their hammers back around 2009/2010.
Some companies have the integrity to perform a recall (cough cough Ruger). Most do not (cough cough DW and many others) .
Things are not always as they seem.