mossberg 600a problem

[shankasaurus]

i got this old mossberg 600a from my pops and im having problems with the forend it doesn't always lock into place and sometimes the button for the action stays up, im not sure whats happening.

[swifty]

Check the nut that holds the forend on. It's fairly large in diameter, on the very front of the forend. If it's loose, tighten it in a clockwise direction.