Hey Ryan,
Sorry to hear about your bad luck with stone points and gobblers. I've only killed on turkey with a stone point so I'm certainly no expert, but I do agree that a shoulder shot with a stone point is no good. My good friend Thad Beckum shot a gobbler in the shoulder with his 58-lb osage D- bow and a cane arrow tipped with a flint point and just like you that shoulder bone stopped that arrow like a cement wall and snapped the point just in front of the notches. He gets pass throughs on deer with that same set-up. That shot was actually on an episode of Turkey Call, the tv show for the National Wild Turkey Federation.
I think that shoulder bone is just bad news for us primitive guys. When I shot my gobbler several years ago I hit him just below the wing and just above the drumstick. Arrow was tipped with a small side-notched black flint point that was 5/8" wide. It went through the soft tissue and slammed into the pelvis on the other side, snapping the point in half. The turkey jumped up at the moment of impact and the foreshaft immediately came out. That gobbler only ran about 30-40 feet before collapsing in the grass. I just missed the lungs but that stone point did a hell of a lot of damage and the resulting hemorrhage killed that turkey within seconds. Stone points are absolutely lethal on a turkey, but you have to avoid that wing bone. I never did find the foreshaft....all i found was the forward 1/3 tip portion of the point still inside the gobbler's chest when I gutted him. Those turkey bones are tough and I was surprised at how much damage my stone point suffered from just hitting a "bird".