I've always asked the same about O1 It's just one of the steels offered. He'll be using RWL-34, O1, D2 and others, customers choice. I for one can't see anything wrong in using 440C if you correctly heat treat it. I've got to admit that I've never looked at 440C in any detail. It is very tough and very effective, so why not?Good stuff, must have taken a little while to get all the shots and tests sorted!
I know 440 c stainless can be pretty usable when heat treated well, but why use it on knife like this? Im not a steel snob, however I do wonder why some big name makers churn out knives in this steel when there are plenty of other (and superior) stainless steels to pick from?