Was that a MAG version of the XTP? I experienced a standard .452" 250 gr. XTP blowing up on a smallish bucks shoulder fired from my muzzleloader at about 1,850 fps. Looking for a bit more information I realized my velocity was about 400 fps over the velocity threshold the bullet was designed for by Hornady. There is a chart online somewhere that shows the designed velocity for each XTP bullet. Exceeding that is very likely to give a blow up and bad end result. There are MAG versions of the XTP that can withstand more velocity. I have since moved to the 300 gr. MAG version and get excellent results on deer from my muzzleloader at about 1,800 fps. It gives the same wallop as the factory non-+P .45-70 300 gr. hollow points. Very accurate also.