Those changes, outlined today for the first time, include more flexible firearm rules for gun and sports clubs, as well as requiring "common-sense rules".
These rules would allow for wider exemptions for farmers and owners of rural land to control pests.
"The Government has unduly focused responsibility and regulation on law-abiding gun owners and hasn't done enough to address access to guns by gangs and those involved in criminal activity," National's police spokesman Brett Hudson said.
He added that the overwhelming majority of firearm owners are good, law-abiding citizens.
National, he said, want to see reforms which focus on people who could pose a risk to society and won't unduly impact law-abiding New Zealanders.
Although National does not oppose a nation-wide firearms register, Hudson said the party does want some clarity around how one would operate.
Police Minister Stuart Nash has been approached for comments, as to whether the Government would consider adopting these changes to get National onside tomorrow.
But it is unlikely Nash would be swayed.
Last week, he said National was ignoring the victims of gun violence by refusing to support the second tranche of the gun law reforms as they are.
He said the party had chosen to listen to a "small, but vocal minority who are set against any change".