NSW safe gun storage laws were softened just months before the death of a three-year-old girl in Sydney's west from a shotgun wound, prompting a call for the changes to be "urgently reversed".

The changes that were passed by parliament in May included removing a requirement for gun owners to attend court and face a fine and/or a jail sentence for breaches of storage rules.

Instead, police are now able to issue a penalty notice.

Police are also no longer required to seize improperly stored firearms and ammunition if they are "satisfied that the failure has been rectified or will be rectified without delay".