Sabotloader,
How much powder were you using, and what was the range the bullets were impacting the soil? Me & my hunting buddies have always had very good results with XTP's of various sizes and weights as long as the velocities weren't in the "magnum" range. I had core/jacket separation a couple times- these were on high velocity impacts (2000 fps+) at close range with the 200 XTP. My friends that use the .452 240 grain and .429 240 grainers have never had (to my knowledge) this problem. Of course they are pushing these bullets at no more than 1750 fps out of the muzzle.
I have no experience on game with the FTX. I did shoot one with the 200 SST and it performed decent, though I wasn't able to recover the bullet to see what happened to it.