It is difficult to find even 10 gauge shotgun ammo today. I have my doubts if 8 gauge shotgun ammo is even made any more, but corrections welcomed.
It is a very large bore shotgun that with solid shells was also used as an elephant gun. It was also used to shoot geese at a long range.
yes
Remington makes a industrial 8 gauge kiln gun.
If your shotgun is a 12 gauge pump, then you have a High Standard Model 200 (Flite King). The standard 12 gauge shell is a 2 3/4 inch shotgun shell. It can be anything from #8 birdshot to a deer slug.
The only length I've seen is 2 3/4 in shells. That is the length of the chamber on my Model 77-B in 16 gauge. Early guns, those made prior to the 1930s may have 2 1/2 inch or 2 5/8 inch chambers, So, while modern 16 gauge shells are 2 3/4", early 16 gauge shells were 2 1/2".
Generally "Pellets" or "Shot" contained in "Shells". There are also solid shot "Slugs" similarly contained in "Shells". I'd use Shells ie "8 shotgun shells", unless you are specifying exactly the type.
Yes, it is larger, the smaller the gauge the larger the bore i.e. 3 gauge is larger in diameter than a 8 gauge or a 12 gauge.
Market or kiln gun
should be 8 shot NOT B (the letter) shot
a few hundred to multiple thousands depending on the usuals
it was make in 1989 i have one