-Find a Flaregun
-Find 2 or more Flare
-Load Flaregun
-Eject (not used) Flare from Flaregun
-Load another new Flare
-Eject this too
-Now you have 2 Flare with an 1 as number in the lower right corner from flare
-Put 1 flare on the other an, do they together.
-Now you have 2 flare on one.
-I make it to an Stack wih 5 flares, i not find any more to this moment so i cannot try it more