Ugh, I gave an action already.
Compelling argument.
You fire your gun at the big glowing weak points across the train. Guided by the hand of the Emperor they strike true, shattering the target to bits. Apparently they where a clever distraction set up by the orks to protect the train! Or maybe Orks just like to add big flashing lights to things. Either way they're gone now.
((Train looses Flashy Bitz))
Following its in-born programming the Ork continues to move forward while holding the trigger down and hoping something gets hit. Nothing does. His gun suddenly stops spitting out brass apparently having run out of ammunition. The second Ork runs closer but looks intent on heading straight into the trench instead of shooting in front of it. Particularly patient for an Ork, the Rocket user simply hunkers down behind cover and waits. It is unclear if it is for you to get near or the train to arrive.
Sparks continue to fly from the track as the train and all its kars fly down the tracks at breakneck speeds. Its kannons roar to life, thankfully not in your general direction apparently finding more flashy targets elsewhere. Still at these speeds it is a matter of moments until those guns are trained on you.
20 meters 8:00 Allied Machine Gunner and loader
30 meters 9:15 Allied Stubber
14 meters 11:00 Ork Gunner 11 Wounds
44 Meters 9:40 Ork Gunner Running
180 Meters 12:00 Ork Rocket User
540 meters 10:00 Engine
565 meters 10:00 Kannon Kar
590 meters 10:00 Loot Kar
615 meters 10:00 Rokkit Kar
640 meters 10:00 Loot Kar
665 meters 10:00 Kaboos
((And for the record you can try to call in an artillery strike if you want.))