Re: 9mm SBR question
Here are some leads on parts.
CMMG 9MM BCG
http://www.cheaperthandirt.com/product/ARR-9441
I know it's not a 7.5 barrel but I don't think 1 inch difference is that much of a deal.
http://www.cmmginc.com/product_p/90d3b00.htm
As far as an upper if you don't mind an...