I've got one like that, that a friend made for me about thirty years ago. Its about twice as big as you need. I found my shooting periodically would go south, and correlated it to how much extra junk I had accumulated in my shooting bag. The only cure was a smaller bag, because if you have the room, you will use it. I now call it my pilgrim bag, and loan it out to newbies. I love the looks of mine I just don't carry it.
Hungry Horse