Not quite sure what a CVS is, but I'm assuming it's the same as a CPL or CCW.
So then, what age should a person be able to purchase a handgun from a Federally-licensed dealer?
Personally, I'm in favor of 18 for each and every one.
I could legally drink when I was 18, I served in the military when I was 18, and I voted when I was 18.
But I had to wait until I was 21 to purchase a handgun, and I waited until I was 54 to get a CPL.
It auto corrected CCW to CVS (as in the pharmacy chain)