Reading through this, one thing that stands out is this is not a guy who was going to be stopped by a few extra gun control laws:
Unlike many lone wolves, Breivik demonstrated that he possessed the intelligence and discipline to plan and carry out an attack that spanned several years of preparation. For example, he joined a pistol club in 2005 just in case he ever needed to buy a gun through legal means in Norway, and was able to rely on that alternate plan when his efforts to purchase firearms in Prague failed. Breivik was also driven, detail-oriented and meticulous in his planning. His diary documents that he was also extremely patient and careful during the dangerous trial-and-error process of manufacturing explosives.
This guy would have kept trying, even if it meant going back to the black market. It seems like he did have the contacts if he had really tried. One thing that’s kind of scary is the fact that there seem to be, at least according to the Norwegian killer, at least fifteen other people throughout Europe who shared his philosophy, and who may be planning attacks of their own.
Actually, it seems like British-style gun-laws (declawing everyone) would prevent this scenario.
Of course, that would just be treating the symptoms, like prescribing pain medication to a cancer-patient: it doesn’t help in the long run, but you can’t beat it for intimidate effect.