1) It's a limitation of the second amendment, not an interpretation.
2) I agree 18 yos should not be able to buy assault weapons. I don't own an assault weapon and I don't know anyone that does legally.
3) You, in feigned ignorance, are intermingling the terms Military Assault weapon, Assault weapon, Military Assault style weapon, Military style Assault weapon, and Assault style weapon. Only 2 of those are or were legal for an 18 yo to walk into a gun store and purchase legally. Please find a description and stick with it.
4) I would ask you to then agree with allowing those under 21 to buy the legal versions of the weapons described above with an honorable discharge from the military, in the military with a clean record or be 21 with no mil service.
5) Or simply consider also boosting the age of adulthood to 21 applying also to selective service and unlimited drivers licenses.
It is so ridiculous that in this country you can enlist at 18, go to Iraq, get your legs blown off, come home at 20 years old and be denied ANY right, much less the right to buy a beer or purchase a weapon that you know more about than most "gun nutz" and 99% of liberals.