Mine didn't come with the nylock screw so I used a lock washer.
Curious since this thread seems to have a couple SW22 owners, does anyone else's gun eject casings extremely violently? When shooting indoors they hit the lane dividers so hard every single case flies off 25 ft in the 11 o'clock direction in front of the firing line. Only pistol I own that does this, and it's annoying to call a cease fire to clean up after myself.