Quite a few. .410 shells were made in 2 inch, 2.5 and 3 inch version, paper, all metal and plastic shells. There are loaded with birdshot, buckshot, slugs, blanks and noise maker shells.
.410 ammo
410 ga
410. Have it checked by a gunsmith to verify what length 410
Yes, they still sell .410 shotgun ammo.
There are hundreds of slightly different types of ammo. For rifles, the most common are ball, blank, tracer, armor piercing, incendiary, frangible and dummy.
It should be marked on the gun- something like .410/ 45 Colt.
None. Some handguns have been made that will fire .45 Long Colt revolver rounds and .410 shotgun shells, but that does not mean that you can take any .410 shotgun and stick .45 handgun ammo in there.
many types of rifle, some pistols like the XP 100 and that is about it.
Not unless the maker says it is safe to do so.
12, 16, 20, 28 gauge, or .410 bore, depending on what it is chambered for.
Do a web search on "12 gauge ammunition types" Over a dozen.
No. While there ARE firearms made to fire both the .45 Colt and the .410 shotshell, they were made for that purpose. Never attempt to fire ammo that a firearm was not made to fire.