Just a public service announcement for anyone not aware. Coldfire siege weapons are able to fire invisble projectiles that the enemies cannot see, nor can they see the ground indicators to move out of the way. By the time they know they've been hit they will be dead.
To find them, complete the dark anchors in cyrodil for a chance to get one from the chests at the end.
This is a horrible glitch at the moment and is causing alot of grief in PvP. Not sure if its on PC but its very present on Console.
Figure the more people who are aware of it/abusing it the quicker this will get fixed.
Enjoy