Do I really need a slug barrel to shoot slugs?

Is there a rule of thumb to follow, when shooting slugs out of a choked barrel? In other words, make sure the slug is so many thousands under in diameter? I’m with Motörhead, as I’d like to shoot slugs or try them at least, on my Bully which has a choked barrel. 



To the OP, I apologize for adding to the diversion. Hopefully with all the talented responses you got your answer.

I'm going to test H&N slugs and maybe the new NSA in my Crown pellet liner (500mm).
You who have had success with slugs in pellet liners, what weight of slugs and size do you use? 



I've read that to small slugs (under 20 grain) gets instable because of the length (or lack of...)?

I use 21and 23 gr slugs in my 500 mm crown barrel

About the same accuracy with both?

I use 21and 23 gr slugs in my 500 mm crown barrel

Click to expand...

Don't know if I have asked before, was that with 0.217 or 0.218 21gr?

I'm about to place a order for the 21 grain ones.

I use 21and 23 gr slugs in my 500 mm crown barrel

Click to expand...

Don't know if I have asked before, was that with 0.217 or 0.218 21gr?

I'm about to place a order for the 21 grain ones.

Click to expand...

218 but 217 work as well

I use 21and 23 gr slugs in my 500 mm crown barrel

Click to expand...

Don't know if I have asked before, was that with 0.217 or 0.218 21gr?

I'm about to place a order for the 21 grain ones.

Click to expand...

218 but 217 work as well

Click to expand...

Great, thanks!