The generic right to defense would include the ability to amount a successful defense against those who are intending evil.
An example would be the Warsaw Ghetto Uprising of 1943. The Jews obtained and used machine guns. That was contrary to the civil law, that denied them arms at all. But all would call that a legitimate defense. If they obtained tanks, that too would have been legitimate self defense.
So, yes, the natural right of self defense can include the possession and use of machine guns, if that is what is reasonably necessary to defend against that attacker.
The right to defense can include having more ‘firepower’ than your attacker. A 90 year old lady could legitimately use a handgun, rifle or shotgun to oppose a 20 year old, 220 lbs attacker with a baseball bat. Or an adult male could legitimately use a semi automatic rifle against a group of knife wielding attackers.
The natural right of defense includes all of that. Any reasonable person would agree that criminals in the US are well armed. Ergo, the natural right of defense would include firearms, firearms capable of deterring or countering the types of attacks that one might encounter.