A Rossi 20 gauge single shot shotgun can fire any factory-made rifled slug, as long as the barrel is marked Modified, IC, or Cylinder. If it's marked Full, it may be too tight for some slugs.
Remington Slugger is a suitable brand.
no
As long as the owner's manual doesn't prohibit it.
Can you shoot a standard slug threw a modified and or improved?
head
A rifled slug- yes.
Shooting rifled slugs is the ONLY way to shoot thru a smoothbore for deer. If you shoot sabot slugs thru a smoothbore, it will not spin and therefore not be accurate. For accuracy, the slug must spin out of the barrel. Either shoot a rifled slug thru a smooth barrel, or shoot a saboted slug thru a rifled barrel.
yes
No.
Depends on what it is choked.
Any non rifled slug. However for best perfomance you want a "saboted" slug.
Yes, but from my experience not accurately.
yes.