A couple of points that I think are being overlooked...
First, The Bill of Rights, grants no rights. The habit of referring to "constitutional rights" and our 2nd Amendment rights is so deeply ingrained that I doubt it is ever going to change, but the fact of the matter is, that no matter how we refer to them in conversation, our rights do not come from that, (or any other) piece of paper.
The Bill of Rights is a list of restrictions on the government, not rights. It spells out what the government may not do, in regard to certain of our rights. And it includes the fact that the rights referenced are not our only rights, and that other rights exist other than, what is listed.
Second, I beg you to remember, if you are old enough, or to learn, if you are not, that the "sporting purposes" clause in the GCA 68 was not actually about gun control. IT is about trade protectionism.
It was supported by US gunmakers (at the time). It was not supported by importers, but that was never expected.
I don't doubt some people are not going to like hearing this, but the fact is that restrictions on what products are allowed for import and sale in the US is NOT a question of infringement of our rights. Any of them.
yes, it's inconvenient. Yes, its a pain in the butt. No, we shouldn't have it, BUT it has NOTHING to do with our rights.
Also, like it or not sport hunting and "sporting purposes" are, essentially games. And the other side considers them trivial, and disgusting games. "Blood sports", etc. Sport = game.
Ever hear anyone make a case that fish & game laws (that regulate seasons, bag limits, equipment allowable for use, etc.,) are an infringement on our rights?
Argue that this one or that one is unfair, or wrong, shouldn't be applied, foolish, etc., one or more of these, or something else, we hear often, but never a peep about our rights. Why? because its "sport", and not a matter of rights.
I believe the government has the moral authority to regulate what firearms are allowed for import into the US. After all, we did give the power to do that to them.
The fact that they chose to use "sporting purposes" as the justification (and framework for their selection process) was simply used as the path to getting the most popular support possible for the actions.
I also believe that just as the govt has the authority to regulate imports, the govt DOES NOT have the moral authority to regulate arms produced in the US in the same manner.
Yes, I know they do regulate them, at many levels, but they shouldn't, under the Constitution. After all, isn't doing that the very definition of infringement?
Still the reality is that we have had about a century's worth of gun control, in ever increasing degrees, and the problems used as the justification for it have yet to be cured, or even significantly impacted.