What year and model is my s&w M&P 15 sport

[Zbrenkus1]

I bought a smith and wesson m&p 15 sport about a year ago from a local shop. It was a bare gun no sights, no scope. Its chambered in 5.56. Recently I've been interested in swapping out the upper receiver, barrel, and bolt group to change it to 6.5 grendel. I'm having trouble finding information on this gun, if its mil spec or not and what I have to do to accomplish this swap. Can someone help me find out more about my gun?

 

[cyphertext]

What you are describing sounds like the M&P 15 Sport II ORC - Optics Ready Carbine. Nothing sold on the civilian market is truly mil-spec, but yes, the Sport is built to "mil-spec" dimensions, meaning you can swap parts without much hassle. Occasionally, you may run into a tolerance stack issue, where two parts are within tolerance but on opposite ends of the scale so they don't quite fit together correctly, but stick with quality parts from known manufacturers and that probably won't be an issue.

As far as your swap, I would just buy a complete upper. Not sure if you would need to change buffer weights since I have never looked into this cartridge.