I just looked it up and you can get the AR platform in 9mm, 40 S&W, 45 ACP, 10mm and 50 AE. Not to mention a myriad of rifle cartridges from .22 rimfire to 50 BMG. At 1,000 dollars or more the .410 would probably be my last choice, considering you can get a really good pump action for 200 or 300 dollars.

Like I said, you make that same gun in a 20 ga with a fully rifled barrel that will fire the modern sabot ammunition accurately and you might have a market for it. There are a lot of states here that are shotgun only for deer hunting and the new 20 ga slugs are pretty impressive ballistics wise.

Paul