It's a good bet, that Walmart isn't going to have any. You honestly could not have gotten a gun chambered thusly, and figured you'd just find a dusty box of ammo sitting on the shelf. If anyone would have (or be able to get) such a thing, it'd probably be Wolverine, but even then, don't hold your breath. I had to google it, and I consider myself to be a gun-nerd. Good luck, but you're probably gonna have to wait until you can load your own, I hope you have brass. It looks like a great idea, if everything that made sense worked, it would catch on like wild fire, unfortunately politics and personal preferences mean a lot more in this world.