Thanks for all the replies.
Like people, all kids are different and they mature at different rates. What is an age appropriate activity for one may not be for another. That is where a responsible parent comes into play. It is the parent's job to first ensure the safety and well being of the child. After that, being cognizant of the first job, the parent must challenge the child so they grow and learn. Its obvious from reading some of this thread that my seven-year old son is much more mature and responsible than some present here were at twice his age.
Matt's been shooting a BB gun for about 18 months now. When he first got the gun, he was too small for the Daisy Grizzly and couldn't "shoulder" it, so he improvised by arm pitting it. Now he has a single shot 22 rifle with open sights, and we've upgraded his Grizzly to a proper pump BB/pellet gun that will bullseye a penny at fifteen paces (I modified the stock to match the LOP of the Henry). He's learning gun safety, handling and marksmanship the right way, and that includes me by his side for quite some time to come. Yes, his starting to learn proper pistolcraft will be a greater challenge for both of us, but we're up to it.
What's really interesting is his approach to toy guns: no interest whatsoever. Sure, he plays with squirt guns, but he's careful to point out to me, his mom, aunts/uncles, grandparents and his friends that these aren't guns, they're Super Soakers, because you "don't point a gun at something you don't want to destroy". Want to have a real dad-moment? Watch your son stalk a friend with a squirt gun/toy with his finger straight and the muzzle pointed in a safe direction.
As for the, IMO, moronic comment that BB guns are safer, we have a backstop in the backyard that would beg to differ.
I considered a BB pistol, but all those I've seen sized for him have terrible triggers. Open to suggestions there.
I spent my lunch at a local gun shop looking at what's available. Sadly, I may need to wait until his hands grow to match his heart. All the guns I looked at had a trigger reach comparable to my Ruger Mk II that is still too long (don't want to start him with a snubbie revo). I'll keep searching. And we'll keep going to the range.
We were watching Hunting with Hank on OLN the other day and Dez Young mentioned that hunting with a lefty is a "good thing" for safety reasons (muzzle direction while walking). Matt said, "Dad, you hear that, you're a lefty and I shoot righty, when can we go hunting?". Soon son, soon (although it will probably seem like forever to him).