OK, the last month I finally had enough time to get a little quality time in with these latest purchases...
Esstac Single M4 Pouch with depth adjustable bungee retention:
When this mag change goes well, it is lightning fast. The pouch is well made and has excellent retention. Here is what I discovered....
The pouch is best used mounted outboard. You should come from behind the mag and sweep the bungee off towards your inboard side. I mounted my Maxpedition RolyPoly on to the exterior of the Esstac pouch and it was a good combo for fast access...when the mag change was fumble-free. The downside is the bungee retention requires more training to master. If you use any type of magpul or Ranger plate, the material is a little more grippy and retards the bungee sliding off - a slick normal GI floorplate works best. Also if you use a magpul or Ranger plate, the bungee occasionally slides off those items but hangs on the corner of the mag body. Though it doesn't seem possible, this can be enough to seriously retard the mag change. The third item is that if your hand traps the bungee while you are removing it, the mag change gets seriously hosed. When you execute well, the bungee system is great and perfect runs of this showed it to be about 0.2 sec faster than the traditional flap system for me. The downside is when you fumble this mag change it is SLOW to recover. I think this would be even faster with A) slick GI floorplates B) mounted outboard, if you carry your mags inboard toward the chest, it will be slower.
One other comment, although these are "depth adjustable" the mag is basically held in by a single ribbon of nylon. If you lift the nylon/velcro attachment, it also lifts the bottom depth of the mag, so the depth isn't really all that adjustable (though it does adjust enough to notice theh difference).
The next item was the
BDS Tactical (formerly SOE Gear) Six-Mag shingle:
Good news: lids are adjustable and work with both Ranger plates and the longer H&K mags. Bad news: The pouches are very, very tight. You can use Ranger plates or GI floorplates; but anything that grips the exterior of the mag (like an old-school Magpul) is a non-starter. Besides that it was a great pouch, the flap system is slower than the bungee retention on a perfect run; but generally performs better. The worse problem I had with the BDS was that the friction on the mags was so great I would sometimes grab the mag and my hand would slip off when ripping the first mag out of the two mag pouch. A Ranger plater or paracord rig for the first mag in the pouch is highly recommended. The good news about the BDS is when you fumbled a mag change it was a much quicker recovery than the bungee system.
Both systems were good quality and had a great deal of attention to stitching, durability, retention and other issues.