Since it's a wool cap it will shrink some if you need it to. This is true, but a general rule with Ebbets hats is to go smaller rather than larger as Wool also stretches easily.

Do fitted hats shrink over time?

Do new era hats shrink or stretch? Even if you don't hear a popping, the hat should have stretched a bit, and it will probably now fit. This is especially true if you've already stretched the hat. New Era hats have a tendency to shrink even after a stretching, so you may have to do this every now and again.

Can you shrink a truckers hat?

Wear the hat as you normally would to shrink it naturally.

The more you wear it, the more it stretches and shrinks to fit your head. Exposing the hat to sunlight or hot water causes the fabric to shrink down to its natural size. Wearing the hat improves the fit even if you choose not to risk the oven or dryer.