IF they are free ranging
IF the range is at all good
IF you don't have more birds than your range can support
IF your range doesn't become poor for large parts of the year as in winter, droughty summers, so on
Then it may work pretty well. That is the traditional way chickens have always been kept.
But it's a lot of IFs. If your range is poor from late fall to early spring then the birds will likely do what they've always done in such circumstances which is they won't lay much or at all. If your range is poor they also may likely not lay much. If you have more birds than your range can support more of the same.
Try it and see how it works. You can always go back to buying chicken feed if it doesn't work.