Another new gun here, Remington 870 + lots of questions

[bsctov]

Paid $250.00 for it, The guy said I cannot use slugs under any circumstances because the barrel is not rifled, i got some of this Remington 00 buck from the store too. I'm confused as to what shells I can safely shoot and which ones I cannot, The barrel says 3 inch and under. Can someone point me in the direction of a good home defense load for this gun? The barrel is not rifled and its a Remington 870 Express.

Heres pictures:

 

[bsctov]

Sorry if this is in the wrong section

 

[JHK94]

This should be under shotguns.

Also, not being able to shoot slugs because the barrel isn't rifled doesn't make sense. Rifled slugs are for smoothbore barrels specifically. Sabot slugs are for rifled barrels...but are okay in smooth ones, as well. I have a dedicated "slug barrel" that is smoothbore specifically for shooting rifled slugs.

 

[Pony Express]

howdy,
nice shotgun! i just picked a new 870 up in the last month too. this belongs in the shotguns section, but moving it would be a hassle so ill just answer your question:
Sabot slugs can't be fired out of a smoothbore barrel, but regular slugs can. however you might want to read the box that the slugs come in to see what choke tube they work best with.

i bought a whole separate barrel for slugs for my 870.