The only XTP I hunted with was their 180gr. and that was shot at pretty HV from a Freedom Arms model 83... I bought the 158gr. FP on recommendation from a mid-west handgun hunter who used them with much success and whose weapon of choice was also the m-83 and I know he loaded them at 1700+fps, but I never got the chance to use them. There is a post on Shooters Bench about this bullet`s use on game you might read..
Sorry I could not be of more help, however, I`am sure some of the members have used these bullet weight`s in their 357 revolvers...What gun are you using??