Luckily the Tiger has a muzzle brake which allows you a great flash position that yields good realism and conceals the flash when not in use. The flash should be protruding right where the barrel ends and the first vent is for the brake. The wires will need to run thru the barrel and are best fed thru it via a fine wire (H L tank antennas work great for this...LOL) or string. The airsoft breach will need to be open for the wires to feed thru to the board.

Good luck, Bob