It can happen with a bullet that readily expands and is not a bonded core or otherwise expansion limited bullet. And, 150 grains is a little light in the caliber, but I shoot 'em, too, in .308. You'll get more penetration with a Federal Premium load using the Nosler Partition or you can go to a heavier bullet like a 180.
I've had one instance where my .257 Roberts didn't exit. It wound up as a little pancake under the off side skin. He was quartering toward me left shoulder forward. I put it right on the scapula from 150 yards, it busted through the scapula, ricocheted up into a vertebra which it smashed, and down into an off side rib which it broke. The skin kept it from exiting.
The deer drop like a sack of taters and I was sort of amazed. I mean, he didn't flinch, he didn't twitch, just dropped completely dead. Of course, after butchering and finding the smashed vertebra I understood why the quick kill. I also understood why the lack of full penetration. I was shooting a 100 grain .257" game king at 3150 fps muzzle velocity and it hit and broke bone on its zig zag course all the way through the animal. Had it not smashed that vertebra, it'd have exited, so no problems that I worried about. I would go for my 117 grain Hornady interlock load on heavier game like hogs. I had one of those fail to expand on a nice, big 7 point once, then shot an 8 point that turned away just as I squeezed the shot, hit him in the butt and the bullet penetrated and expanded nicely and exited the throat!
It penetrated a ham and broke a pelvis on the way through. But, I don't use that bullet on deer because it will fail if you don't hit heavy muscle and bone. That deer it failed on, it went behind the shoulder between two ribs and exited the off side toward the last ribs. I couldn't find the exit hole because it was exactly .257" diameter. That deer went 75 yards before it dropped and didn't leave a blood trail.
Anyway, you've got to choose a load that expands. You don't want too much penetration. The best, most sure fire way to get the best of both worlds is to go to something like the Barnes or Nosler Partition. I don't know about the Barnes, I handload, but the Partition is available in Federal's Premium brand. I really like the Barnes bullets. They're solid copper, expand at low velocities readily, but only back to the base of the hollow cavity. They have a couple of other advantages, boat tailed with good BCs, and they are longer for their weight which means they act like a bullet with higher sectional densities. My 140 grain Barnes 30 cal I load in my .308 is actually longer than my 150 grain Nosler Ballistic tip bullet, yet I can drive it faster because it's lighter and it's a great penetration bullet. I've used it on one big hog and it went all the way through the animal which had a pretty good gristle plate. I'm not sure if you can get the Barnes bullet in a factory load, another bonus for the handloader.
The old time way to insure you use a bullet that works is to use a 200 or 220 grain round nose in .30 cal. It will expand and it will penetrate, the same reason the .30-30 has been do good all these years, that big, blunt nose. But, you are working with a pathetic BC in such a bullet. However, if you're not shooting over 200-250 yards anyway, it don't matter. But, with the Barnes bullet, you get your cake and can eat it, too.
Anyway, I think you probably just hit a lot of bone. 150 grains is normally a good deer sized bullet in 30 cal and what I use normally on deer. If I were still hunting instead of stand hunting, I might want a heavier bullet or to use my Barnes load shooting at game running away, but I'm usually on a stand with the gun. Still hunting isn't too productive around here, too much thick vegetation and the deer hole up in it during the day. You have to ambush 'em moving in the mornings or with a feeder. Stand hunting, I can wait for my shot.
