X bullets BC's are largely exaggerated. Mathematicaly, they have a high BC IF they were jacketed lead which has a better "specifec gravity" function. Solid copper has a very low SG function which hurts the BC. Terminaly, they are great if you dont hit a big flat bone at a sharp angle. They are also much harder more times to shoot accurate enough to entertain most shooters found here. Bottom line: Low BC, hard to get accurate (not always) and cost alot more than other hunting or match bullets.
AMAX's, ACCUBONDS and SMK's (SMK's if you match the bullet to the velocity and game you are hunting which goes for hunting bullets too, just SMK's can be more finiky) all do VERY well for much less money, higher BC's and better overall accuracy.