This has turned into a great discussion!!! This is what I like about forums.....especially this one. NO EGO'S OR BAD ATTITUDES.
The bear hides do shrink quite a bit during the tanning process but the thing that really makes it confusing is the fact that a bear hide gets overstretched lengthwise during the process.
I remember doing my first lifesize bear. I had just finished stretching out the bear and took a length measurement for reference. I then looked at my catalog to check out the options for a bear that size. This is where I started to panic. For a length like I had....the girth was over 20" too small.
I then did some research on a taxidermy forum and found that, without measurement from the carcass to go from, stretch the girth as far as it will go and use that at a starting point.
I followed that advice, increased the girth by 20"ish inches which in turn shortened the length of the bear to a size that was proportional with all of the manikins in that size range.
Lifesize bear mounts are a tricky thing.
Now...even though you have the measurements from the carcass...that doesn't mean there is a form available for that particular size. This is where a taxidermist earns his money by reshaping and resizing the form to fit your particular bear.
Ever run your hands over a bear mount and feel folds and wrinkles on the skin? The form was too small!!!! Some wrinkles are gonna happen but I've felt big folds before which just meant the customer got a mount back smaller than what it should have been.