Seems like a good buy for an AR10, buy the upper and lowers on special and pin them together for a complete rifle:
http://palmettostatearmory.com/index.ph ... ng-handle/
http://palmettostatearmory.com/index.ph ... eiver.html
I included shipping with both in my cart, not sure if you have to buy them separately to avoid the 10% excise tax. I believe these use the SR-25 pattern mags, DPMS pattern (works with the Magpuls).