Boyd,
While Dave was Alive, I purchased a few bags from him with the Ultra Fabric. The bags I bought were not filled when I asked him what is the best fill, and I stated the I have heavy sand, he told me about the Black Beauty. He didn't mention the mix. I filled a few bags with Black Beauty, and liked it so much that I had other bags that I drained the Heavy sand out of. If you think filling bags is a Pain try emptying bags. I then filled them with Black Beauty, those bags were Leather ears, not Ultra Fabric. I like the Ultra Fabric, and I like the Black Beauty. But I would still use Leater ear bags and Black Beauty, But I have lost taste for Heavy sand. It settles too hard and the guns bounce too much.
Also, I am set up for Bag Squeezing... I don 't use the knobs and trinkets on these new fandangled front rests, I just aim and shoot. It's simple and it works for me.
Paul