I think the question requires a definition. What exactly is bullet failure? It seems we are all considering this definition much differently.
I have read this statemet several times in my life now: "At what point during the animals death did the bullet fail"
Or the bullet exited with a bore size hole so it could not have expanded, must have failed.
Well, with any opinion somebody relates it needs high resolution to have any credibility,.........at least to me. How significant is a single event to try and prove or disprove a theory or function? As many of you know my background, you know I don't refer to single events to draw my conclusions from. I'm also not stuck with a single firearm type, caliber or cartridge. My hunters bring everything under the sun to shoot with archey, muzzleloaders, handguns, you name it I've probably had somebody hunt with it. They typically take well in excess of 100 big game each year. In the last 13-15 years I would say without question they have taken more then 2000 head of big game from the tiny steenbok up to the elephant. This does not incude the many years working in Alaska with goats, both species of bears, deer, wolves, cariboo, moose, etc.
With this kind of resolution you would think bullet failures would be seen eventually on at least some of these species. You would be correct. But then My definition of bullet failure may not be the industry standard (whatever that is) or even another persons opinion.
My simple definitions are
#1 lead and jacket seperation at any point after impact.
#2Not penetrating in a dead straight line.
I have seen both of these more times then I can count with cup and core bullets, I have seen the lack of straight line penetration more times then I can count with several versions of the Barnes X bullet.
In order to have seen or witnessed these failures I would have had to recovered the game. So the theory of "at what pint during the animals death did the bullet fail" is absolutely silly to me. If the bullets performance was unacceptable and you still lucked into the location of the dead animal why would you trust it on a second animal?
I could go into a list here of specific animals just from last season that I have seen failures on. However it's a safe bet that cup and core bullets are not the prudent choice for todays hunting where big game is important to recover. The original "premium" bullet is the Nosler Partition. Fully three times the cost of a cup and core bullet when released and remained double the cost for many years afterward. This was the baseline bullet for big game for probably 20 years or more.
Today you can buy a bonded core bullet which is so vaslty superior to the partiton at less then half the cost of the partition.
Recent catalog prices for example:
165 grain .308 Nosler Partition 23.16 per 50
165 grain .308 Hornady interbond 31.39 Per 100
165 grain .308 barnes X 28.83 per 50
165 grain .308 Swift Aframe 44.18 per 50
Standard cup and core bullets
165 grain .308 Speer 17.42 per 100
165 grain .308 hornady 16.15 per 100
165 grain .308 Sierra 17.58 per 100
I have seen everyone of these bullets shot and recovered. The majority of the cup and core bullets in many little pieces with the jacket seperated.
More then half the partitions recovered had no front half lead core attached. Not automatically bad. It's the design to do this. However it does leave many people with a bad feeling to see a bore diameter exit hole even though the bullet had violent internal expansion. It's still not as good at retaining the momentum of a bullet that will retain all its weight or the majority of its weight. It's also hard to beat a bullet that doubles its diameter or more and can maintain that dimater. Those exits leave a hella good blood trail!
I suppose in the end it's up to your definiton of bullet failure. Regardless if it's a sub 3000fps cartridge or over. Standard cup and core bullets will crumble and seperate. The frequency of this is higher the faster they travel. Standard bullets from a 30/30 work well, standard bullets from a 30/378 are a failure waiting to happen. If the issue is an important one for you then shoot the cup and core bullets all you want for practice, then switch to the premium bullets for use on game. At least that's what I do with my rifles.
As far as my recommendations go, sub 3000fps rifles will work far better with the Hornady interbonds. they are soft and stay in one piece very well. Rifles over 3000fps might be better with A frames. They are much harder and withstand much higher impacts better.
I would say the same for most bigger bore rifles as well. When shooting 338 or larger the A frame would be my bullet of choice on the bigger species. If you're lucky enough to have a rifle that can shoot the newest versions of the X bullet then that is a great choice as well. Not all rifles deal well with the X bullet though.