Mossberg shotgun question

[RUGER]

Saw a shotgun at walmart the other day and I have never seen one like it.

http://www.mossberg.com/products/default.asp?id=5

Thunder ranch 6 shot is the model.
My question is the muzzle.
What is the purpose of the saw tooth looking end on it?

 

[RUGER]

OMG I just googled breach barrel !

LOL I want one !

 

[memfuzz]

Think of it as a non slip chin rest for the bad guy.

 

[Model70Man]

That is used to take the core out of apples.

 

[DaveB]

It is a Halo Xbox kind of thing. You stick the barrel in the door or wall, like a knife in wood, and pull trigger. Really.
Like mentioned, its a breech barrel as in breeching a door.

Insane.