Thank you all for the very helpful feedback

As to what has changed on my setup: I have been shooting the same equipment for three seasons. Three years ago I made a heart shot on another buck but never hit a rib going in, so that tells me nothing. Before that I shot a heavy setup (2219s) at 70 lbs and blew through everything but wanted a bit more arrow speed.

My draw is 30 1/4 inches. (I am 6' 4" with long arms)....so yes my arrows are a bit underspined. Have not had any problems tuning tho with broadheads or field tips...But maybe that is the problem I am looking at. I shoot lighter 100 grain field tips sinceI do quite afew 3-D tournys.

As for the blade catching the rib, that was what I thought originally. However, I very closely inspected the rib and in both instances, my arrow tip hit the rib. On my kill this year, the tip (which are prick-your-finger sharp) just caught the back edge and splintered the back part of the rib, then the blade came by and cut it almost in two...but at the same time changed where the arrow was heading.