Hello Geno,
Never used the DK on american deer but tested on some roes, wild boars and red deer does and corsican ram. Calibers where 7x64 (about same as 280Rem)and 30R Blaser. Works well, very accurate and act a bit like a partition or a former grand slam (twin core). The front expand a lot but the tough and protected rear goes on and generally exit. Will surely be good on muley and whitey. Even elk if well placed.
Dom
