exactly. It has to have enough speed for the yawing/tumbling to result in fragmentation. And that is what achieved with modern weapons like M16, AK74.
>The idea that they are somehow specially designed to do that is an urban myth.
For example the 5N7 5.45 AK-74 bullet, the "poison" one, had an air-pocket in front between jacket and the core. We don't know whether it was intentionally designed to enhance the tumbling upon hitting the body - we do know it did significantly enhance it.
>occurs when a bullet that is near maximum stabilization undergoes sudden structural stress.
yep, yaw upon hitting target at short up to medium distance when the speed is still close to maximum.
> That is literally the opposite of trying to make a bullet tumble.
in that in previous sentences you're conflating bullet stabilization/tumbling during flight with the tumbling upon hitting the body. It is 2 different things.
>They aren't any more or less cruel than the cartridges they replaced.
Higher fragmentation and higher tumbling makes them more cruel. There is also shockwave issue from the higher speed, yet it it is outside of the type of effects we're talking about and is a topic on its own.
>US weapon and cartridge re-designs have incidentally eliminated it in pursuit of other priorities.
and as i already mentioned in pursuit of other priorities USSR/Russia moved to more stable round. So at least we have that.
This is actually common on a lot of rifle bullets. Search for OTM or open tip match. There are some open arguments in the gun community about it's effect on ballistics etc, but it actually comes from a by product of the manufacturing of the bullet. Most FMJ bullets have the copper skin formed so that it's open in the back, OTM bullets are "backwards" and are run through a form after the lead is poured. This shrinks the area of the opening in the shell and pushes it to the center. Which makes it easier to keep things radially concentric and balanced. Something that's very important at longer distances.