I don't like to say someone else is wrong, because oftentimes there are a lot of variables involved. I just say what I believe to be true, based on long term experience. There is plenty of room for other experiences and opinions. That's how you have a worthwhile discussion. Sometimes something will be absolutely wrong. Then I will say what I think or say nothing.

As for the springs, they have to be of good quality spring steel and correctly heat treated. I've seen plenty that aren't. The S&W (carbon steel) mainsprings have been consistently very good over the years except for the SS ones they made for a while. Those have an S stamped on them. They are junk.