Use this stock if you have a shorty M1A just like a SOCOM or Scout Squad model With all the shorter barrel. This stock is made of a proprietary carbon fiber composite which makes the stock powerful yet lightweight. The magwell is relieved of material so magazine alterations are rapidly. https://sage-international-firear07273.weblogco.com/29590226/the-ultimate-guide-to-m1a-ebr-chassis