Judging skull size is real tough. A few years back,my group of friends took 4 bearsonopening night. 2 215lbers, a 375 lber and a 400 lber. The 375 lber was an older bear than the 400 and had a larger skull at final measure, but looking at them you would have sworn the 400lber had inches on the other. The 375 had in excess of 20"'s and the 400 lb bear was just shy of 19" if I recall correctly. There was no way you could have seen it looking at those 2 bears side by side.

My suggestion if you are looking for a P&Y bear is first hunt an area where they grow them that big. Then I would hold out for a really old looking bear. Some younger but really large bears will measure out smaller than the grizzled old timers.

Others may have better info, but I worked for a bear guide in Maine for 4 years and watched an awful lot of them and I can't say I could truly judge a P&Y skull while in the woods.

For weight comparison, we took a 535 lber with hounds that measured out less than an 1 1/2" less than that 375 lber.