Modifying a cast V spring

[satwel]

I am building my first lock from castings. It is a large military lock and I need to open the cast frizzen spring a little because it doesn't quite touch the frizzen when the frizzen is in the open position. How can I safely spread the two leaves apart? Is it simply a matter of heating the fold and prying the top leaf up a little? The spring is still as cast - not hardened or tempered yet.

Thank you.

[Mark Elliott]

I would adjust the spring red hot even though it might not be technically necessary if the spring is annealed.   You can't be certain of the state of the casting.