Magical Beasts arent something that we have in the wild, so it's not like we can really explain it. But if you want something based in reality Ill try my best. If the tensile strength of the beast armor is that of Tungsten or harder, grown as a lattice in order to be flexible - then a 1980's sabot round isnt going to do much against those materials. We use Carbon Steel on tanks simply because its weight ratio and cost, which is nowhere near the mpa of Tungsten which would be extremely expensive regardless of weight. Naval ships are typically of similar strength, but theyre steel percentage varies. Now add in the lattice part, and you'll understand that its flexible and reinforced by the meat of the beast which makes absorption even more relevant. The kinetic energy will dissipate through the beast with relative ease in comparison to a solid armor a tank has. A BMG round for example would/should stun this theoretical beast and quite honestly knock it back - but we can only assume that it would be a bad bruise from one round. Add in whatever other magical properties you want to instill and you have your impenetrable beast that needs to be worn down. Regeneration, reverse polarization, frequency disruptor etc.
I get the silliness of arguing this sort of thing, but since we're doing it, might as well continue. I enjoy these kinds of hypotheticals.
You made an assumption right off the bat about beast armor being at least as hard as tungsten. I could maybe agree with that assumption if we're talking about some kind of giant turtle monster's shell, but there are very few real life creatures that have skin that is what we'd consider "tough" to that degree. Yes, I know, magic creatures. But there isn't a very long list of creatures alive today that could shrug off a .22 without at least a little damage. Now shoot it 100 times with that .22 and you probably kill most things, or at least wound them so badly they stop trying to eat you. And the creatures that could survive that sort of attack the best would do it more with loose skin and fat layers than armored hide, like say a bear.
But a .22 is a far cry from something like even a 7.62, let alone a .50 or 20mm or higher gun. Those weapons are designed to tear shit up, being particularly good at tearing up flesh. So unless the creature is completely invulnerable to the rounds, a few are going to get inside and start tumbling around and wrecking things that shouldn't be wrecked. And a sabot round is literally a rod of high density material designed to penetrate heavy armor via inertia. Even if the sabot round and the armor are made out of the same material, the sabot has a fuckton of velocity behind it, so the armor has to be much denser to just shrug it off. So again, maybe a turtle monster, but that's gotta be some powerful magic if it is that thick on a flying creature or one capable of running/burrowing really fast (Rathalos and Diablos).
Yes, no one can win this argument because magic. I understand that. But it still bothers me, because to me it is pretty lazy for them to make literally every type of modern munition worthless against them (unless you shoot it in their mouth obvs). Let them tear a few up with their guns like it should be, maybe even kill a Diablos with them. But then they run out of ammo and a second one appears, so they're fucked. Don't just make all that shit worthless, but a bone sword (how do you even sharpen that shit if it is that strong to begin with?? do you have to kill a stronger monster to sharpen this monster's parts?) works no problem.
EDIT: Btw, for those that haven't watched it yet, this conversation was more entertaining to me than most of the movie.
