I found this on CMMGinc's web site. Link is below go down about a qtr of the way.
CMMG G3 Mag Compatible .308 Stripped Lower
CMMG is proud to offer our new .308 G3 mag compatible semi-auto lower. Upper is compatible with DPMS .308 upper receivers with minor modification to upper receiver to allow for clearance of wider G3 magazine. With new mags available $3-5, this is a combo that cannot be beat. Lower is compatible with most popular aftermarket triggers currently on the market. We are accepting pre-orders.
SKU Number:L009
Price: $449.95
http://cmmginc.secure-mall.com/shop/?cart=1501840&cat=38&
Cool idea. If it can be done on the AR10 platform. I would think it can be done on the XCR.
CMMG G3 Mag Compatible .308 Stripped Lower
CMMG is proud to offer our new .308 G3 mag compatible semi-auto lower. Upper is compatible with DPMS .308 upper receivers with minor modification to upper receiver to allow for clearance of wider G3 magazine. With new mags available $3-5, this is a combo that cannot be beat. Lower is compatible with most popular aftermarket triggers currently on the market. We are accepting pre-orders.
SKU Number:L009
Price: $449.95
http://cmmginc.secure-mall.com/shop/?cart=1501840&cat=38&
Cool idea. If it can be done on the AR10 platform. I would think it can be done on the XCR.