I had an old and worn out gun belt (The kind with two rows of adjustment holes)that I was going to get rid of.
Before I trashed it though I had a thought that I could make it into a sort of sling pouch. It assembled well. I haven't been able to shoot it yet because of the massive storm in the US North East, but it looks good.
I believe in giving credit where due. This sling is simply a modification of the Dan Bollinger design found here
http://www.slinging.org/20.html. For all braiding instructions please refer to his article. I could really write it better.
I started by cutting the leather from the belt in two polygon shapes as pictures. I made them eight spaces in length, with the first and last sections having one of the holes removed by an angular cut. Make sure to leave enough leather around the singular holes to leave them sturdy for the stress of throwing, about an 1/8th of an inch or more. It's important to make them an even number of rows in length so the weaving will leave the strings entering and exiting from the leather in the right way.
After braiding the retention cord as per Mr Bollinger's instructions I came to the point where you'd normally split the lines, and braid the pocket. Instead of braiding I put the strands through the first hole of the belt leather from the side where the ammo would be loaded.
I then weaved the lines in and out of the spaces along the outer edge of the leather, exiting at the other singular hole on the other end.
I then repeated on the other side with the other piece of leather placing it to mirror the first.
To finist the sling simple continue braiding the lines as per Mr. Bollinger's instructions. The finished pocket looks like this.
And holds well as illustrated by my tennis ball sized metal sphere.
Give it a try.