Can anyone tell me what the tightest choke tube you can use to shoot slugs through?
Thanks for the Help.

Full. But IC is recomended for slugs.

So a modified would also work correct?

Yes it would work. I would deff try and see how it groups though. Youll get the best accuracy out of an IC choke. What gun are you using?

I'd go with an IC choke.

i would go with an improved

To be clear, we are talking rifled (foster-style) slugs in a smoothbore.

Yes, they can be shot through a full choke, but either modified or IC will probably be more accurate. Remington sluggers may workbest if you only have a full choke, as they were intentinally a bit undersized. You still need to try a few to see for yourself what your gun shoots.

I would not shoot any other style slug (sabot or hybrid) out of a full choke, unless the MFR indicated it was OK.

They are the old style foster slugs. And the gun is a NEF pardner.
I shot it today and they seem to group well but shoot a little low (3 inches at 40-50 yards). No big deal just have to remember to compensate.
Also tried to shoot them thru my 870 with the rem choke and a modified choke but they were really low thru this gun so I wont let anyone use this one. It was like a foot low and 4 inches to the left on every shot thru this gun. Consistenet but way too off to try to compensate.
Thanks for all the answers I appreciate it!

If you are shooting saboted slugs out of a smooth bore accuracy is going to suck regardless of choke. The saboted slugs are made for a rifled barrel. You would be better off buying several brands of rifled slug and see which are the most accurate out of your shotgun. My 870 like the Federal Tru-ball slugs.
As for choke, a rifled slug can be shot out of any choke, but IC, Skeet, or cyl. Bore will give you the best accuracy.