fanny packs are almost an instant give away that you are carrying a gun. I do have one but now I use the Wilderness back pack with a carry strap. It blends in with the rest of the population carrying computers or electronic components. They come in all sizes and it is very sturdy. The pack has many functions and there is a place for an extra magazine and other accessories carried in the top flap. The sides are velcro and access to the firearm is quick and easy. Take a look on their web site for the video of the back pack. I know you will be sold.
Nick