To the OP, Gamecock is technically correct. In certain circles, a fight of some sort will break out similar to calling a magazine a clip.

The M&P10 is more of an LR308/SR25 format than an AR10. The problem is that most of these rifles made by the various companies have something proprietary about them and they do not follow a set format like the AR15 does. So calling it any of those names is technically incorrect but if you are going to use one the DPMS format or LR308 format would be the closest to correct. Also, when it comes to getting parts and accessories, the DPMS, LR308, SR25 format is what you'll be looking for. AR10 stuff, to the most part, will not fit. Even then, some stuff you will need to pay attention to. For example, the rail height on the M&P10 follows only one of the LR308 formats set by DPMS, low or high but off hand, I can't remember which one it is. One of the hand guard threads will answer that question.