I don’t see how that line of reasoning helps in a Catholic context. The same could be said of nuclear, biological, or chemical weapons, yet all three are condemned in CCC 2314.
With that said, I’m unaware of any condemnation against owning guns. There is an implicit condemnation against arms races in CCC 2315, and one could argue that the reasons given could apply to the hoarding of guns, but that’s not clear. At the very least, the language isn’t particularly friendly towards the concept of owning guns with the hope of deterring violence.
However, CCC 2263 - 2264 does give us the right to defend ourselves if the intent is preservation of life, not the taking of it. As such, in a country like the U.S., where gun ownership is allowed, a gun could reasonably serve that purpose. In a country where gun ownership is forbidden, we should refrain. The Church does not declare owning a gun - or any weapon - as moral, but it does give us a “duty of obedience” to government (CCC 1899 - 1900) except for in cases where they go against moral law (CCC 1903), which again doesn’t include allowing gun - or weapon - ownership.
Rocks and stones were created by God, but we found ways to weaponize them. Guns are closer to that weaponization, not a natural resource like rocks or stones.