I know there are a few groups of compatible upper/lowers in the 308 family of ARs, my question is, can I mount an M&P10 upper on a DPMS patterned lower? They appear close in pics, but I don’t have access to a M&P upper to verify the fit between that and a DPMS style lower.
I have no basis to test my assumption but I would have to say that they should work together. The upper has proprietary parts but it will still fit on a AR-10 sized lower. There is only one way to find out and that is to try it.