I have a Remington 1100 with a 18 inch "slug barrel" on it.   I know it is meant to shoot slugs as the barrel does have rifleing.   Question is can you shoot any kind of shot shells like buck shot, lead or steel or is this going to eat the rifleing up and ruin the barrel.

Shotshells probably would not hurt it, but the rifling probably will not allow for accurate shooting. I figure that it will throw the pattern off, but that is just my opinion.

You can shoot the other loads in your slug barrel. The shot does not touch the sides of the barrel during firing because the pellet are contained in the shot cup.

The Remington 1100 is a great shooting gun. One suggestion. An 18" barrel is too short for serious clays shooting, if you plan on doing this you might want to look around for 28" smoothbore barrel for your shotgun.

Two examples of how poorly shot patterns out of a rifled barrel. I shot 3 times at a chipmunk with 1 1/8 oz. trap loads with 7 1/2 shot size at a range of just under 20 yds. after the third shot and the chipmunk had not even moved because he didn't have a pellet hit close enough to scare him I gave up and went back in the house. This was out of a 24 inch Hastings barrel. I told my good friend who wanted to try buckshot out of his, he didn't believe it was that bad. He set up a 3 foot square piece of cardboard, shot at it 3 times with 3 inch 00 buck at about 20 yds. put 1 pellet in the cardboard.
Tuco

I think that the rifling would cause the wad cup to spin thowing the shot pattern off at all angles.

Thanks guys.    I was thinking about home defense but it sounds like the pattern spreads too much.

Tuco you sick bastard.... :)

SPLICER:
If you want a HD gun, this might do.  Most people have problems getting ENOUGH shot spread at the short ranges inside a house.  The problem would be if you had to shoot at longer ranges.

I prefer a smoothbore for my 18" HD shotgun. I want the tightest patterns I can get. Every stray pellet is potentially dangerous to innocent bystanders. I can always switch to rifled slugs if I have to.