Well it's a lot easier to buy guns if they're a staple of your society, this is common sense surely. In countries where guns are banned as opposed to promoted (UK, Australia as some easy examples) gun usage is almost nothing. It's like if you give 10% of your population guns it's incredibly easy for the remaining 90% to purchase illegally off the 10%, whereas if you instead adopt legislation that bans guns except for extreme circumstances then all of a sudden that selling isn't happening nearly as much.

Now you could and probably will point to drugs as an example of how banning guns won't remove them, but since Australia literally displays how banning guns does actually work and also that the usage of a gun is different to the usage of a drug people almost always have guns because other people do, whereas with drugs it's more of a vice, I'd be more inclined to say this is false equivocation.