Well.....I see you're just writing about super simple subjects. LOL

So much can be gone through and it's almost dinner, but a few thoughts.

I hear what you're saying, but I think a much greater thing affecting this, a "change of the times" is not the weapons, but the attitude or level of maturity of youth today. I know this kind of follows the old joke about suddenly sounding like your father, but it's what I've seen.

The gun issues happening today, didn't happen the same way 20 years ago. But to disagree with you, ALL these types of weapons existed. The AR-15 is almost 60 years old, AK-47 well you know what the 47 is. Perhaps not as prevalent in 1968 when the 18 yr old requirement was put into effect....but Colt was selling the AR-15 "sporter" at that time and had been for an undetermined number of years prior to 68.

So throughout the preceding years, the weapon and it's "types" were readily available. My first was a Mini 14. Yet at some point things changed....and it wasn't the firearms or their availability that changed. One can debate a multitude of things that may have.

HOWEVER.....it also is a fact that things have changed. Perhaps another possibility is not changing the age, but the requirements for that age. You pointed out the training of kids joining the military....perhaps adding required training and testing, both written and practical. Military service being taken into account.

I don't know how effective having a "cosigner" would be in stopping anything. Parents that disagree with the law would simply sign for their 18 yr old without necessarily making them learn anything about the weapon.

Much to think on.