I just got back from a gun show...

[SAWgunner]

and this booth had a .50 BMG and a rifle exactly like it beside it that was chambered for a .408 something or other.  It looked somewhat like a .338 Lapua Magnum but, of course, it was bigger.  Anyone have any information on this cartridge (with the little information I gave you, heh heh)?

[Yukon Jack]

As a wild guess, I'd bet it was something like the .408 Chey-Tac.  This round is gaining a lot of ground in the 1,000 yard matches.  I've seen some incredible claims of distance of supersonic flight and ballistic coefficients remaining around .9 all the way to around 3,000 yards.  Whether true or not, I don't know.  I think the cartridge is based on the 505 Gibbs.

http://www.extremefirearms.com/Pages/Cheytac.html

[SAWgunner]

That would be it.  Thanks for the information!