Depends on the BA, distance, type of buckshot, load velocity.
Yes
16 gauge, 2 and 3/4 inch, any shot from fine birdshot to buckshot.
Not really. They can match the gauge and spread pattern to distance from the target and barrel length, but nothing conclusive.
The Short answer is yes. Even in a 410 gauge shotgun with a full choke. Remember that a "410" is 41 caliber or .41 inches in diameter. oo buckshot is only about .32 inches in diameter. The same is true for shooting slugs in a shotgun. There is no safety issue involved. You will notice that there is no warning on the packaging of the ammunition. In our litigious times you can be sure that if there was a problem there would be a warning printed on the box.
Yes.
That will depend on the size of the shot, and not the gauge. Fired across level ground with the largest buckshot, a shotgun has a maximum range of between 600 and 700 yards. Not a usable range- just the furthest that shot will travel.
You will have to experiment to find out.
Yes
Depends on projectile size. # 9 shot probably won't travel 200 yards, but 00 or 000 buckshot or a deer slug might travel over a mile.
How 'bout a slug or buckshot.
Yes. The Mossberg 500A1 is a .12 gauge shotgun.
either 12 gauge slug or buckshot to the head.