The former prime minister and architect of Australia's restrictions on gun ownership, John Howard, says gun control laws should be strengthened, not weakened.

Asked about the controversy surrounding the Adler shotgun, which some Nationals MPs have been pushing to allow access to, Mr Howard said the country's current system of controls had worked to make the country safer.

"My position as you might expect on gun laws is I don't want to see any weakening of any kind in the prohibitions that I introduced and which may have been added since 1996," said Mr Howard, speaking after an event to mark the 100th anniversary of his alma mater, Earlwood Primary School.

"Now, as to how the government of the day deals with the current issues that's a matter for the government of the day but my principle as everybody would accept and expect is I don't want to see any weakening of our gun laws," he said.