Lack of expansion sounds like more of a bullet problem then a caliber problem. Teamed with a fast expanding bullet 7mag will do just fine on deer (though it may be a bit overkill). I've had success with 140 grain and 150 core lokts.
The only problem I have ever had was a couple years ago I had a core lokt appear to blow apart when I shot a doe from 10 yards. She was perfectly broadside when I shot and hit her right behind the shoulder killing her nearly instantly. However when I got to the carcass it appeared that the bullet did a 90 degree turn and came out the front of her brisket and it was kind of a ragged exit hole. But I think this was just a freak incident at extremely close range, I've shot other deer with the same round at ~25-30 yards and the bullet worked flawlessly.