As I understand it, the God Given rights aren't the specific guns themselves, just simply the inherent right a person has to defend themselves from outside forces who wish to take away ones inherent right of life, liberty or pursuit of happiness.

In a world where guns exist, that just so happens to be the best means at which to manifest that right.

We have the right to bear arms, which is anything to be used as a means of protection. Semi auto gun, full auto gun, rocket launcher, sword, etc. It's not a right to a specific type of gun. It's a right to any tool you wish to use as a means to defend yourself.