On another topic on the gunsmithing section, a person posted something to the effect that most any 50-60 yr. old action probably has a weak striker spring. All my hunting rifles are that old. So should I assume that is correct and replace the springs to potentially improve accuracy?

NOT TRUE!!!
I have several 1816 Muskets with perfect springs, (V springs), and many bolt actions over 100 years old with perfect springs.
Not that some won't get weak, but mostly, no.
He might be blaming his poor shooting on weak springs. Don't work that way.