Started out shooting a model 42 at age seven or eight. The gun was purchased new specifically for me by an adopted uncle who lived across the street and he would take me out to his W. TX ranch in the summers, sometimes for several weeks at a time. We would stop in Ft Worth or Weatherford on the way out and he would buy a case of cartridges for it, usually 2.5" rounds loaded with #6 shot. I shot jackrabbits and rats mostly, the latter being the most fun. There was an old delapidated barn long ago left to go fallow with some remnant hay and other grain stuff in it and the rats, big ones, lived in there with impunity most of the time. I would sneak up to the big end doors and then open one as quickly as I could and shoot the rats running up the walls and along the rafters trying to escape the sunlight. I could do that several times a day, somedays. I would normally get a couple of shots before they all disappeared. Can't recall ever being able to get the third shot off while they were still running about, but I did get where I could hit them running with good regularity, same for the Jackrabbits. The gun stayed at the ranch along with two others he had purchased for me. It disappeared with the others shortly after he died. It was found much later that the individual who took them had pawned them for some good time money.
My first real gun at home, mom's strict rule 'NOT before age 12', was a Winchester 62A .22 RF that I still have and use. I had a Daisy model 25 at home from about age five or six, but she didn't consider BB guns a threat or a problem and she was was not anti gun, rather she got the age 12 thing from something the young post war mom's had access to, most likely a widely circulated popular magazine or country club talk and gossip. I don't know, but I do know that dad honored her wish. We kept the 42 and a lot of other off premesis stuff between the 'men'. I learned to drive while out there too; pick up trucks, tractors & cars. Charmed times, those, and I value them immensely.
I have a nicer 42 today, but that original field grade gun was the one that helped to produce the fond memories. I don't even recall how it was choked; not sure that I even knew what choke was at that time and to be honest, would have cared less .. both the rats and the rabbits died when hit.
I started shooting birds on the wing with a Mossberg bolt action with a nozzle that was shortly replaced by a 16ga. Stevens of the 311 genre; the former was just awkward and the latter kicked me like the proverbial mule; from there to the present it has been many trades, some mistakes, some successses, but mostly continuous misadventure with friends, dogs and laughter whenever the opportunity has presented itself.
Was the .410 a handicap? Probably.
Do I regret that I was started with one? Are you kidding?!
Would I start a young person with a .410? No.