Evening Bear;Miss Rose: Since you asked about the EBR..If you do a copy and paste, this will show you what the Sig 556 looks like and tech specs.
http://www.sigsauer.com/Products/ShowCatalogProduct.aspx?categoryid=35
www.sigsauer.com
This should work, I tried and it came up for me.
I'll be watching your mods ... may feature in my NaNo this year!