Never plan on being able to shoot through a moose or elk shoulder blade first off, that's a poor shot placement.
Secondly there are too many factors at play to be able to do that. Including where on the shoulder blade you hit.
I like 400gr minimum arrow weight, I have 78-79KE I made a poor shot on an elk this year with my first shot and at 15 yards (quartering away from above) I didn't get through the shoulder blade. I have had complete pass through a on 5 other elk and my second shot was a passthrough too.
I was able to stop him at 40 and put one where it counts. Now I have a cool memento to my hunt and a reminder to make sure everything is set correctly before I take a shot.
LC