44 Man, howdy. On cowboy hats you will see at the rear of the sweatband a seam where there is usually a bow. At the base of the seam nearest the hat itself you will see a bead. Carefully fold your sweatband down and with a sharp pair of scissors, snip that bead. It has a monofilament line, like fish line , in there and snipping it will give you a tad more room in your hat and it will be able to stretch a bit, with the cord cut.
That dumb bow there does nothing. The way I hear it, back in the old days of stetson and the boss of the plains hats the bow was functional. They didn't make as many sizes as today, and the bow was actually a string inside that could adjust a bit your size. The outside hatband was supposed to help in that regard too. :grin:
Those plastic hat stretchers they sell in western stores look like the would stretch a hat too, at least keep it from shrinking.