What kind of clamp do you guys think works the best for holding 2Ar mags together?  Ive seen Mag-cinch but anyone have better experience with something else?

I've used the cheap metal clips, duck tape, para cord, you name it.  The Mac-Cinch is still the best I've used.  The only problem is that the top round of the non-inserted mag keeps bumping forward after firing the first mag, making it impossible to insert the second mag if the round is far enough forward.  It really does make the two mags a nice little package, though.

I had a friend give me a ready mag.  He is SF and said it would not hold up to the abuse they gave it, but that its perfect for 3 gun competitions.  I put it on the AR the other night and I like it. Its easy to install.  I haven't got a chance to use it in a competition yet, but it did speed up mag changes.  And unlike tape or mag clinch you can reload it without tools.

The only draw backs I can find to it are its heavy ( as heavy, as a loaded mag ) and it crowds the bolt release.

I met a custom holster maker this weekend at a match and asked if he would make a clinch system for AR mags out of polymer.  He is currently working on it.

Ever heard of a sport called Airsoft?  They make mag clamps that work great.  www.redwolfairsoft.com