Dude, I'm telling you it's EXACTLY the same. Not close, not just a different model number digit, the exact same gun from the exact same assembly line. Do you think Sig cares if Walmart sells it for $900 and your LGS sells it for $1100? Either way, Sig is selling it's M400. And when Walmart carries it, they are selling them by the truck load. Sounds like perhaps you should double check your LGS for honesty.
A good plan executed today is better than a perfect plan executed at some indefinite point in the future.
- General George Patton Jr