uncock

To straighten or flatten (remove a cocked shape).

to uncock a hat

To let down the cock of (a firearm).

My heart jumped up amongst my lungs. I never waited for to look further, but uncocked my gun and went sneaking back on my tiptoes as fast as ever I could.

And d'Artagnan set the example. Then, turning toward Planchet, he made him a sign to uncock his musketoon. The Englishmen, convinced of these peaceful proceedings, sheathed their swords grumblingly.

To open or spread from a cock or heap, as hay.