The Supreme Court hates to revisit recent rulings. Even if the majority of a court disagrees with a previous ruling they will let pass 20-30 years before they revisit it. In 2008 and 2010 the SC ruled that handguns are a core element of the 2nd amendment and that there is historical precedent for citizens to own and bear arms, independent of any affiliations with militias. Essentially they ruled all US citizens have the fundamental right to own and bear handguns, full stop. It was only handguns because the court challenge was against a handgun ban in D.C. and Chicago (overturned by the SC, obviously).
https://en.wikipedia.org/wiki/District_of_Columbia_v._Heller
You are completely right that Congress could pass gun control laws, they may be challenged to the SC but they could dismiss it as long as it doesn't fall afoul of the Heller decision - ie any ban on handguns would be struck down, but for example if they changed all long guns to be classified as NFA weapons that could perhaps be ignored by the court for a later court to decide.
So all you need to do is get a filibuster proof majority in the House and Senate and a President who won't veto the legislation. The last time one party had a filibuster proof majority in Congress was 1937. Oh, in the current climate any politician who supports gun control is also immediately recalled out of office, but no doubt that will also be easy to get around.
To pass a full gun ban you would also need 2/3'd's of the states to vote to amend the Bill of Rights.