According to my sources the .408 CT is based on a .505 jeffery case necked down to .408. It fires a 419gr bullet at 2890 fps. Bullets available are HP BT match, Soft Point, AP, API, and Tracer.
There are many verions similar to this round as I mentioned the 50 BMG's necked down to .40 cal and there was the 9x90mm chamber for the WSG2000 prototype HK that fired a 340gr bullet at 3440 fps. That is smoking.
As good as this sounds, it is hard to imagine how much better it can be than a .50cal, 660gr Match bullet fired from a .50 BMG sniper rifle at 3100 fps!
Thanks for the information.