i ran in to this problem a few days ago. i had an 044 with a 20" bar. in a hurry, i didnt' inspect the face or i would have seen the the center further back than it should been and known that was the gonna be a problem on the back cut. i had to go deeper in the center to get the wedge out even after i bored it twice from the front and busted it out with an axe. i couldn't reach the center on the back cut. i was in a bad situation for a minute. moral of the story is after the tree is cut up to the hinge i cant see any way to trip the center except with a longer bar which i didn't have on the job or from the face side. dont get stuck in this position i was lucky i had a rope on the pole and the ol' dodge power wagon pulling it. 4-low saved me