Open action looseness is controlled by the forend, if you have a wood forend with spacer, you can shim tween the spacer and forend to tighten it, but if it's not loose when the action is closed, there's no harm, it's just disconcerting. If it's got a synthetic forend, only a new forend will tighten it unless you make a change to the forend bolt hole somehow.
Tim