Subgun AR sling?

[Hutch]

Not really a subgun, but a 10.5" pistol with a Sig wrist brace.  I really like a 3-point sling, but with no buttstock, I can't figure this out.  Btw, it's a dedicated 9mm lower that accepts Glockazines, from 33 round G18 mags to 10 round G26 mags.  It's heavy, but a real hoot to shoot.  Single point slings are not familiar to me.

What do the cool kids use?

[AJ Dual]

Hmm...

Probably just a QD mount on the front rail as far forward as practical, and a end plate sling mount. You could also just run the end of the sling through the velcro brace straps on the Sig Brace, and it would be like one of those T-shaped buttstock loops for an A2 stock.

[Boomhauer]

I don't really care for three point slings. Too complicated IMHO.

There are two slings that I will abide by. Quick adjust two point (which gives you pretty much all the advantages of a three point without being overly complicated). It shines when you need to be able to go hands free, still need to keep the weapon on you, but don't want it smacking you in the nuts.

and

Single point- very simple, just a loop around your body and lets you drop the gun. The single point slings work great with short barrel guns, not so great with longer barrel guns (because they will smack you in the nuts when you drop it)

For sub gun style use as you envision I'd use a simple single point with a quick release, with the attachment point placed at the buffer tube/receiver area as is common. You don't need the stability of a two point for an SMG style gun.

[dogmush]

Magpul MS4  (or equivalent )

Single point attached where the lower and RE meet, that can be un snapped and turned into a two point to snug down. That's what I use on my AR pistols.

[MechAg94]

I am picturing a QD sling mout on the hand guard and at the back of the receiver with a strap through both.  Just something to keep it against the body until you lift it to fire.

[dogmush]

I'll take pictures of my set up.  It's pretty slick.

[dogmush]

I completely forgot that I traded away my KeyMod forward QD attachment in a deal for a barrel.  Gotta buy a new one.

Watch this video:

https://www.youtube.com/watch?v=qhldyYv2fQ4

The first minute will cover the cool bit, then he goes into more detail.

This is what I run on my AR pistols.  I have two of these slings that I just move around as needed.  I tend to single point the pistols, and two point the 16" carbines but it's nice to have the versatility on all of them.  It works well if you have to sling up for a long shot as well. I also don't move the rear QD.  Just unclip the front and clip it to the gun.

[Zardozimo Oprah Bannedalas]

For sub gun style use as you envision I'd use a simple single point with a quick release, with the attachment point placed at the buffer tube/receiver area as is common

That's what I use on mine, and the attachment at just that spot.

When using a 2-pt sling, I use the same rear attachment, and the front attachment just forward of the magwell.

Many options for rear sling attachments:
http://www.gggaz.com/sling-attachments-en/ar15-m16-sling-mounts.html