James Williamson and 1911 Syndicate crew go into why H&Ks product lines here in the US are… thin.
The answer is the combination of US and German regulations on the import/export of “military” weaponry. The Germans are VERY sensitive about selling commercial weapons that are similar to their military rifles. We in the US want the military rifles, semi-auto, but we want them to remain the MP7, G36, or 433, and not come in a neutered format like the SL8.
In short, H&K has a hand tied by the ATF and the German government and making an importable variant is insanely expensive. You have to submit it for approval and await both import and export approval from the ATF and German government. The Germans are meticulous about the paperwork and justifications for selling their select-fire systems or their non-commercialized inventory.
The US had a similar series with the AWB guns and making certain that the commercial and military weapons were indeed very different. Colt, most famously perhaps, used different trigger pins and a very different semi-auto bolt carrier in their rifles for a long time to differentiate the commercial rifles and the select-fire assault rifles.
So listen to James, HK doesn’t hate us. Not really. But they can only do what they can do, they aren’t the only company experiencing these setbacks and covering rough terrain in the pursuit of getting product into our consumer hands. The ATF can literally, at will, just decide that a gun that was good isn’t anymore, and does. The same goes for imported parts, which can be declared a firearm… just because.