Depends on what choke it has.
This should be a Mossberg 500 in a Montgomery Wards suit. Check any dealer for the availability of a slug barrel.
yes
Yes, but, DON'T DO IT!!!!!!!!
Yes, but, it is an exercise without a point.
A properly loaded shotgun shell slug load, yes.
No
At this time no,there are not any available.You could have a model 1300 slug barrel redone and have the gas ports added to this barrel.Then it will work fine in your model 1400 Winchester shotgun.
"Cylinder" is the safest choice, no question. "Improved Cylinder" is just big enough to allow the slug through, but the slight restriction might produce enough overpressure to cause cycling trouble.
As long as the slug barrel is smooth bored(does not have rifling) then it can be used with bird shot.
no
Yes.
Yes, you can shoot a slug from a Marlin Model 55, which is a shotgun designed for shooting slugs and buckshot. It is a smoothbore shotgun, making it suitable for firing rifled slugs. However, it's essential to ensure that the slug is compatible with the specific gauge of your Marlin Model 55 and to follow all safety guidelines when using it. Always check the manufacturer's recommendations for the best performance.