I'm thinking of making a rear leaf sight for my Marlin 30AS, and I would design it something like what's pictured here -- a Marbles flat top or a Winchester 22g. Are sights like this made from plain steel or spring steel? I realize the main part of the sight has to flex in order to accommodate the elevation adjustment. It seems like the spring tension, imparted by that flexing, helps hold the elevator down and in place. But the amount of flex and tension seems moderate. I welcome input on what type of steel would be best. Thanks!

[Linked Image from i.ibb.co]

[Linked Image from i.ibb.co]