how to attach a sling to a shotgun?

[Barms 98]

i have a standard HD 18 inch 12 ga..

 

how do i attach a sling to it? i've been poking around it appears that swivels are sold separately from slings, correct? where do you guys attach the swivel on the muzzle end? is there a replacement clip for the tube or something?

 

I have a Blackhawk specops butt on mine, looks like there's a hole in the bottom for a clip/swivel. I'm not looking for anything super high tech.. just something i can clip on and off easy. So i assume you permanently affix the swivel to the weapon, and then just clip on off/the sling when warranted?

 

If anybody can post some links or suggestions to parts it would be much appreciated. I think a standard 2 point is fine. And i think someone will ask me what it will be used for.. it definitely is not for hunting.. just something that would get my hands free if ever i had to be on the move with it.. ya know?

[djg0770 481]

You can get a replacement magazine cap that accepts a sling swivel.