Not sure exactly what you are looking for, but

here's a nylon sling and here's a cotton military style.

I use surplus M14 slings.

This is not gonna help much, Otony, but the best rig I have found for that duty is a surplus BAR sling. It's 1 1/4 inch wide, but the extra length allows you to mount it on TOP of the stock. I installed an extra swivel on top of the stock of my nightduty 870 and looped the front end around the magazine tube extension. Adjusting the sling then allows the gun to hang naturally across the front of your body and leaves your hands free to open doors, etc. A mounted light indexed with the sights is good if you need to shoot from the low position.

If you put the top swivel just about 1" or so forward of the buttplate it does not interfere with mounting the gun. This rig looks a little funny, but it works great.

That said, the big problem now is FINDING a BAR sling. It looks just like a Garand sling but is about half again as long. Gun Parts Corporation is where I got the last one I have, but that was a while back. The newer squad automatic rifles may use a similar nylon sling if you can find one of those.

.....at work this morning I found a very thick 1.25" cotton sling that I was able to utilize with a set of 1" Hush Stalker swivels.

Apparently that brand of swivels is a trifle generous in its dimensions, so the larger width sling went in with just a small bit of binding and resistance.

What I had been looking for was a source of 1" slings or webbing similar to what Magpul utilizes on their line of slings, as that stuff is quite soft to the touch. I had hoped to find something just as comfy (?), but this cotton sling will work just fine.

I'd post a few pics, but sadly the board still seems broken in that regard.

Otony