None of these other things mentioned are analogous to guns.
Why the fuck not? You've said this over and over: pray, do expand at some point. Guns are a commodity, yes, but their purchase, ownership and use are all actions which conform to exactly the same semantic rules as rape or murder.
People are going to buy guns anyway, all you do by criminalising it is ensuring only criminals do it.
People are going to rape people anyway, all you do by criminalising it is ensuring only criminals do it.
People are going to drop motherfuckers anyway, all you do by criminalising it is ensuring only criminals do it.
When all I have to do is swap a verb and an object to make your argument look ridiculous, it's not a sound argument.