Until I find the right barrel-mounted side swivel that will work with an HBAR profile, I'm going back to an old standby.  We used to tie these back about a million years ago (ok, only about 10-12yrs but it FEELS like a million).  You might have to re-tie every couple of weeks, or maybe a little more often if you're really humping it, but this little trick actually works pretty well.

Front takes a roughly 30" piece of 550.  Rear is a simple loop made from a ~8" piece.  Ends are burned hard, knots are all square.  Front has the added bonus of silencing the sling swivel.

works for me!!!![

Wrap the ends with 100MPH tape and I bet you won't have to re-tie them very often.  

IIRC, it isn't so much that it comes untied, it's more that everything stretches out and the sling swivel gets loose.  I might try it with something with a little less stretch, like spectra-cord.  Now, if I could only find some black or OD spectra-cord...

Hal9k,

Have you seen the GG&G "Sling thing" that mounts inside the front sight? That might be a good alternative to your field-expedient arrangement. Not cheap, but nothing from GG&G is.

Your solution is fine for general use, but that nylon para-cord will melt if you heat up that barrel enough (say, a few 30-rounders in a minute). Besides detaching the sling, that will make one fine mess to scrape off of your AR (I know, I've done it!).

You're not kidding, man!  I forgot to take one off after a night-fire exercise once.  You know, when you burn up all the unused rounds so you don't have to turn them back into the ASP?  I can remember thinking, "what's that smell?" after about the fourth mag.  I realized what it was when I tried to sling my rifle later on...

Thanks for the tip on the GG&G part.  I found what I was looking for, though.  I'm going with the M203 mount that pins onto the barrel.  It should be here early next week.