Sigil of Battle....source ?
It’s found only on dropped weapons. People then salvage and put them on the TP. By now I think it’s safe to assume the wiki has updated all craftable sigils’ pages with their recipes, so doing a quick search there will almost always give you a reliable answer.
                                    “Any lump can hack bad guys to death, but it takes skill 
and style to turn them into craters and dust.” -Tonn
Number-crunching for ecto salvages – periodically updated
                                
                            and style to turn them into craters and dust.” -Tonn
Number-crunching for ecto salvages – periodically updated
You can get it from salvaging exotics with that as a sigil, or you can craft them from forge (small chance)
                                    [Permabanned on Forums]
[Currently Inactive, Playing BF4]
Magic find works. http://sinasdf.imgur.com/
                                
                            [Currently Inactive, Playing BF4]
Magic find works. http://sinasdf.imgur.com/