Cat Hunter - Is there a reason why you have to use expandables? Not picking a brawl, just curious. /ubbthreads/images/graemlins/smile.gif I notice you are shooting 2312's, so I know your not shooting an ultra fast arrow. I also see you shoot a bow which has a good brace height.
With a well tuned bow and 2312's @ 70lbs, it should be no problem getting good flight with a sensible arrow rest.
A good fixed blade broadhead is always the best choice unless you absolutely can't get good flight, which means something is wrong with a bows set-up.
I gave expandables a try over 10 years ago, and killed all the deer I shot that year, but I had some penatration issues. Less blood trail, and a few longer that usual tracking jobs on good shots.I know what the "field tests" say on mechanicals, but I know what my own eyes have seen.

Fixed blade broadheads have NO equal in penetration.
If I was hunting large bears I would have a perfectly tuned bow shooting a heavy fixed blade boadhead. The mechanicals will work on a good shot well, but if the shot is less than perfect, the fixed blade will still get the job done.
Whitetail have a fragile set of ribs, and expire quickly with a well placed arrow. A bears ribs are about twice as tough, and he is well muscled. You can easily kill a bear whith mechanical heads, but a fixed will get you surer results.
Trust me, I have SO been there done that too!!!
Good luck Cat Hunter!!!! /ubbthreads/images/graemlins/wink.gif