ETA: resized pics as per stickman's advice.
disclaimer:  the camera I used is not that great.  It is a digital camera with a long exposure time, and so on the shots where either the photographer or I are moving, it tends to blur just a bit.  sorry.  props to ImageShack for hosting

ok everyone, today's review is of the build your own tac sling as depicted here.
The rifle being used to test it is an RRA A4 20", RRA Dominator sight, Eotech 512.
All sling materials totalled about 12 bucks.  (24$ for 2; made one for the scattergun as well)
The pistol is a SW1911 5" in a pancake ccw holster.  I normally use a Safariland 6004, but forgot to bring it out with me that day.
I am testing the usefulness of this sling for 3 gun matches, so it will  be transition drills I am trying out.

Here is the range I will be running all over, the 100 yard rifle/ full auto range:


Here I am with the rifle:  (yeah, I know, it's a cheesy way to blur the face)
You can see how well it hangs in place without much fuss, ready to grab.



Here you can see me right after I snatched the rifle from the ready position, and have fired a few shots.
I began by shooting close range, then moving long.  (the poor photographer had a bad time catching me, for some matches you are required to sidestep a bit while shooting, so I am doing that.)
The picture here is of me shooting a 4" metal square at 75 yards, so I am in a bit of a twist-lean-lock position.



Next is the drop.  In the interests of really knowing how it handled, I didn't follow it down,
I just let go (after putting safety on) and watched where it fell.
You can see how the sling is already pulling the rifle off to one side, e.g. the "holstered" position.


As soon as the rifle hits my left hip, my hand is on my right, drawing:


Here I fire a few shots from the .45 at a 25 yard target.
The stock sort of bumped my chin a bit, but it's an A2, a shorter one wouldn't do it.


Conclusions:
Good sling.  It flopped around a bit too much for my liking, at first,
so I tacked a quick loop of webbing around the part of the sling that runs along the receiver,
and secured it around the narrowest part of the buttstock where it threads into the lower.  
This made the sling hang a lot better.

With a bit of practice, it was not hard to get the following sequence under 5 seconds:
ar15 shot at 25m target
safety on ar15
transition
1911 shot at 25m target

Pros:
*cheap
*fast transitions
*can use various arrangements of quick-releases to facilitate offhand shooting
*fairly comfortable, I used polypropylene webbing and it's very smooth
*durable.  I was able to hook both ends of the sling adapters on a chin up bar and hang on the sling without incident.

Cons:
*cannot use sling to "sling up" for long/difficult shots, as it is way too long.
note: it might be possible to rig up an extra loop in the sling somwhere to serve this purpose, I am working on it.
*sometimes an A2 length stock will club you in the chin on the way down
(not an issue with a shorter stock... tried in with the scattergun and it wasn't a problem)
*if you have a gut like mine, you might get poked in the tummy by your pistol grip on the way down.
*while the sling was easy to make, the A2 buttstock and forend adapters were NOT.
(had to be sewed, and took me a few hours)
if you have side mounting points fore and aft, this is a non-issue

Final remarks:
Overall a very nice sling.  Would I trust my life to it in battle?  No, because I do not trust the sewing I did on the A2 adapters.
But for matches with fast transition requirements, this is very nearly a perfect sling.  9/10

Thanks for reading!

1.  You might want to resize the pictures so each pic can be viewed without scrolling all over.  

2.  When you get a chance, take your photographer out and beat him/ her.

3.  Lastly, a picture of your gear laid out would make sense so people could see what you are talking about.

Quoted: 1.  You might want to resize the pictures so each pic can be viewed without scrolling all over.   2.  When you get a chance, take your photographer out and beat him/ her. 3.  Lastly, a picture of your gear laid out would make sense so people could see what you are talking about.

1)  done, should view ok at 1024x768
2)  i like that idea
3)  took those, but came out too dark, will retake them when i get off work