There is a lot of rubbish spoken about the 410 and its killing power.
The individual pellets of No 6 shot out of a 410 move at the same velocity as those from a 12, 16 or 20 bore
There is less shot from a 410 so you need to keep ranges a bit shorter, and / or use a tighter choke, but provided you can hit a bid with a few pellets it will not have any issues with old age, or lack of adequate pension etc.
Challenge with a 410 is the smaller pattern which makes it more difficult to hit a clay or a live bird.
If you use a 410 and treat the head of any bird like a midi clay pigeon you can kill just as well as with a bigger gun. I shot my first (and only) canada goose with a 410. It was a single barrel Ward Patent by Army and Navy. It came over at tree top height, I swung through and it dropped stone dead. I was about 12 at the time. I have shot plenty of pigeons, a few ducks, phaesants, rabbits and squirrels with a similar single barrel, or my side by side WJ Jeffery.
And its my favourite gun to shoot clays with.
A 410 is often the tool of choice for farmers and small holders to kill cattle, pigs and sheep. A shot Cartridge to the brain is deadly.
And with slugs, where legal, plenty of deer sized game is killed every year. A 410 slug is about the same as a 44 or 41 magnum rifle or handgun in terms of effectiveness.
At the moment the only non lead cartridges are bismuth. In the US, Tungsten Matrix shot in a 410 is being used with great effect by Turkey hunters. One day manufacturers will introduce steel shot 410. I strongly suspect that such cartridges will perform just as well as lead, but suspect patterns will be tighter so a little harder to hit with.
I haven’t used Bismuth 410’s. I have made the personal choice to only use non toxic on any game that I shot and eat. So I am using a variety of 12 and 16s for live game shooting. 410 is for the clays.
I might buy a box of bismuth for use on woodcock. I have one oak woodland which does get woodcock. A potter with dog, a 410 and coming with a brace of woodcock every now and then will make a box last a few years.