Step 2: Cutting your ammo pouch
...no, not THAT kind of fun with leather, that's another site that takes your credit card info before you see the good stuff. Its all free here! Anyways...
Take that scrap of leather I told you that you would need in the intro and... WHAT? You don't have it yet? Fine, we'll all wait for to get your bit of leather and come back.
. . .
...are we all set? Good. Take that 2" x 3" rectangle of leather and cut it into a crude diamond pattern, like so. This shape will give you the deepest pocket for shot once you shoot this thing for a few weeks and the leather starts to stretch out in the middle.
Punch some holes a little bit smaller than the outside diameter of your tubing at each end of your pouch about 3/8" from the edge of the leather. This will give you a bit of leather to fold over itself to strengthen the pouch where you'll tie your tubing.