Might be a silly question, but do I get the AR-15 or AR-15 version of the PRS stock? I had read the M&P 10 rear end was .223 sized, thus the confusion. Thanks guys!
Both the AR-15 and the AR-10 PSR stocks fit on a regular A-1 buffer tube with the A-2 spacer removed. The difference with the large frame AR's like the M&P 10, is that the charging handle comes farther to the rear than the AR-15's. The cheek riser on the AR-10 PSR stocks is 1/2" farther to the rear than the AR-15 model to allow you to pull the charging handle to the rear without the riser interfering with the charging handle. Look here for an illustration AR10 FAQ and information-Small Update 2012 - AR15.COM
The AR-10/SR-25 PRS is the one you'll need unless you plan on leaving the cheek riser flush/down all the way or otherwise modifying the cheek riser if raised by cutting a relief for the CH to clear.
