440 grades have fairly wide ranges of carbon content. Any of the 440C still makes a good knife but the difference I've seen in just different suppliers of 440C I would in no way put my name on anything of lesser grade for hunting or other heavy use. The 440A and B used in production knives is what has turned a lot of people away from 440 in custom knives. There is no reason for this as some 440C is as good and has as high or higher carbon content as ATS or 154CM. The sample pieces I got from Carpenter over the last year had an analysis of 1.14 carbon content in their 440C. It is some good stuff too and you can tell the difference when you put one to the test.
As Dan said the other grades may be a good choice for a dive knife. I wouldn't buy any but a free piece may be a good choice for making butter, spread knives, wedding cake knife, etc, for formal events.