The ones that expanded most likely hit the beef bones.
Most probably. But, that's not my point, and its a point that probably won't be all that popular here, today.
I don't feel that "ball" FMJ .45 bullets
should expand. Ball isn't for that. That's what expanding bullets are for.
I love expanding bullets, use them for defense and hunting. I was always very fond of the Speer 200gr "flying ashtray" .45 slug. Have a small supply hoarded, for defense loads. They work in my guns. And I have some pretty hot loads for them.
Ball (230gr FMJ) is for ammo that works in everything. Its for when expansion is not needed thing, just a nice to have thing. Ball is for reliable function and penetration.
The .45acp isn't an extremely good penetrator. Fat, slow and rarely very pointed bullets aren't real good for that. Adding built in expansion to the bullet risks reducing the penetration.
There is a balance act in play, and if you can get both, by all means use them. send me some, I'll use them. But not every real world situation balances the same, and adequate or even outstanding expansion does not make up for inadequate penetration.
Placement trumps all, when penetration is adequate. If the bullet goes where it needs to go, it will work. Expanded, or not. If it doesn't get there, what else it does matters little.