I have the same bag, however I got an even smaller one to put around my waist like a fanny pack,ç when I'm actually hunting and now use the bigger bag to keep extra supplies in. In the smaller bag I only keep what is necessary to fire the gun.
Cards, caps, shot measure, shot and powder flask. I buy 110gr spouts and the cut them to length based on the load I have for specific game....dove load, duck....that's what I use for my sxs anyway. Want to replace the plastic bottle with a shot pouch. I wear it behind my back and then spin it around to the front to load. It even has a place for a water bottle. May not be "traditional" but if they were available back then, they would used them.