That's an interesting point though. In Poland, you can own certain guns, right? A Polish friend of mine told me he owned various guns, including semi auto pistols.I know you can own these in other central European countries too, like the Czech Republic, Switzerland and probably others. These guns can generally fire at least 15 rounds as fast as you can pull the trigger, and you can reload in seconds. The Virginia Tech killer used 2 of these to kill 32 people.
Now I'm sure my friend had to go through more extensive vetting than they have in the US. But here's the strange part: many US mass shooters would pass these checks anyway. Not all, certainly. But many would. So when you say "they do not find a way to get the guns", you're suggesting that the potential mass murderers are out there, looking for a way, but failing to get the guns. But clearly they should be succeeding occasionally, the legal way. And yet we don't see it. Why not?
We need to know what else is different about the US. But why complicate things by comparing the US to vastly different countries? Why not compare it to a mostly similar country: itself from the recent past. The US has had essentially the same gun laws forever. There have been 2 major overhauls to US gun ownership: one in the 30s and one in the 60s. Other than that, basically no changes. But these mass killings are fairly new, having started in earnest in the late 90s. Why? It's not surprising that the body count has increased, since AR-15s are more deadly than the kind of guns Americans used to commonly own 30 years ago. They have become incredibly popular in recent years and are very cheap and accessible now. But as I pointed out earlier, there's nothing stopping anyone from racking up a huge number of victims using the kind of semi automatic pistol that has been around for over 100 years, and we do see this in the US.
This question weighs on my mind all the time. What is different about the US? I feel as though I know the answer, but it's ephemeral, hard to put words on it. Everything is more extreme here. Success, failure, happiness, misery, love, hate. So in a sense it's not that surprising that the crimes are more extreme too. But I know that's not a very useful observation. I just know that it's 100% possible for people to be able to own guns, and for this stuff to not happen. Hopefully it's possible in America too.