I was just thinking at that distance it should have went completely through her. Do you think that the 150gr powder charge was what caused the problem with penetration at that close of a distance and yes I know i don't need all that powder but i shoot it without any problems and i shoot it very accurately. Any opinions ?
It may seen counterintuitive, but less range and therefore more velocity does not necessarily mean greater penetration. In fact, the opposite can often be the case, as you've observed with your deer.
With the wide range of performance capabilities (and shooter preferences) today, muzzleloader bullet design is often a compromise. The problem is that the same bullet that is designed to expand perfectly at lower velocities with standard loads (75-100gr BP equiv.), will overperform at the much higher velocities of the "magnum" loads. Like you saw, the bullet overexpanded and disintegrated, causeing reduced penetration (but undoubtably massive internal damage to whatever depth is did manage to penetrate to). The opposite can also be true. If the bullet is tough enough to expand correctly at high velocity, it may not expand at all at lower velocity. The unexpanded bullet may (and probably will) go straight through, but the wound channel won't be as dramatic. It'll just punch a nice clean hole.
The problem for the designers and manufacturers of ML bullets is that they have no idea what charge level the end user intends to load their rifle at, and "one size" doesn't fit all. And unfortunately they don't often truthfully market their bullets for the perfomance level they're meant for. Which is a shame, since while the PB you used may have fragmented it was still able to do the job on a small deer, but if you'd taken the same shot at a 600lb elk there's a good chance there'd be a wounded elk out there with you back at camp wondering what went wrong through no real fault of your own. I wish ML bulet makers would be more upfront about the velocity range their bullets are meant to perform at.
Mike