I don't doubt there are tougher 180 gr 30 cal bullets than the 180 gr NPT out there today(Banes among them),since the bullet was always designed to be "soft" in the front to expand even at low velocity and longish range. IIRC it has less bullet behind the partition than a 200 gr does,so the 200 gr in general will penetrate somewhat deeper.
I've used both from the 300 Win Mag and the 300 Weatherby. One bull, killed at 450-500 yards,caught a 180 placed on the shoulder joint;he collapsed to the shot,and the bullet was recovered against the hide just forward of the off side ham. Another at about the same distance fell to the shot with his head up...a second bullet to the neck broke it,and exited opposite the entrance.
Another at about 250 yards had two blow out the chest on pure lung shots.Sometimes you will recover a 180 Partition and sometimes you won't...seems to depend on impact velocity and what you hit.
I have been on site when a medium sized brown bear was killed with a 300 Weatherby and 180 NPT,and he was a pretty dead bear...like "right now".
I have driven the 200 gr NPT from just forward of the haunch all the way to the off shoulder, breaking it,and exiting....that seems like a lot of penetration for an expanding bullet.
A pal showed me a pair of 200 gr AB's fired from a 300 Weatherby at 350 yards,and started at almost 3100 fps,recovered from a bull elk from last fall,with hits similar to what I have done with a 200 gr NPT...they had good frontal area,which I guess helped stop them, but with similar hits, I have never seen a recovered 200 gr Nosler Partition.
Based on what I have seen,I would use the 180 or 200 gr NPT on any elk hunt, anywhere without a thought to which was better....not suggesting they are "best" but IME they are thoroughly reliable game killers.
I try to pay attention to some of these penetration tests shot into media, and published here and there....one thing I notice is that Barnes and Partitions generally lead the pack for depth of penetration,or at least are at the top of the heap for expanding bullets.
On thing to keep in mind when it comes to 300 Win Mag factory loads is that not all of it will break 3000 fps from a 24" barrel with a 180 gr....this is fast but not up to full potential and not in the 300 Weatherby/RUM class ;generally I think the bullets will take those speeds and behave pretty well at the distances most of us shoot animals.
Never used a Barnes on an animal...my supply of other bullets is too deep and I may not get to them any time soon,so can't supply a head to head comparison.
