So I literally learned how to sew about 3 hours ago. I'm 19 years old and never in my life did I take an interest in the Fabrical Arts...until I went on diytactical.com and saw all the amazing things MEN could make with cloth and string.
As of right now, my main (and only) chest rig is a Chinese SKS 10 pocket chest rig. With this rig, I can fit AR magazines in it but it's such a tight fit that in a combat situation, it would be wise to not try and fiddle with trying to get the mags back in the rig. That's where a dump pouch comes in! So I ran to Wal Mart at 11:30 at night to buy some fabric and left with some Rattlesnake patterned fabric.
This is what I made, remember I learned to sew 3 hours ago, so bare with me:
First I made my main piece. It's roughly 14"x28":
Next, I took two 2x5" pieces and sewed them in half to make 1" belt loops:
Then sewed the top seam with a large enough section in the middle for a drawstring. Again, a little crooked, but it works:
Then sewed the belt loops on. They're about 1 1/2" from the top, 3 1/2" from the sides, and 2" from eachother:
Then I sewed the actual bag's sides and bottom:
I flipped her inside-out, and put a shoelace for now! And we're in business!:
With a PMAG in the bag:
As you can see, there's lots of room, but that's because I it doubles as a Gas Mask bag if I needed!