I deal with terminal ballistics for a living, both on the performance and countermeasure ends.
A number of anecdotal experience is not a scientifically valid test, nor has a quantifiable performance criteria been established to test against?
How many inches of bone blind performance is acceptable?
How many inches of penetration in calibrated medium?
Retained weight?
Velocity window for optimal performance and thresholds for failure?
External ballistic goals…aerodynamics, internal ballistics-sensitivity to distance off the lands, etc?
The thing is this- A small, but vocal, group seems to think that any of this is new information. It’s not. You can read books from Ruark to Boddington with everyone in between and get thousands of anecdotes on bullet performance, both good and bad. Weatherby wrote and promoted a very similar idea- velocity + fragmentation = shock/death. It worked very well…but not all that consistently on difficult targets.
It’s not that you are wrong…a 223 is lethal on many animals under optimal conditions. The problem is that a lot of field shooting involves sub optimal conditions. That doesn’t mean the 223 is wrong…just that it has performance limitations.
There is a long history, with literally millions of rounds fired, that created modern bullets and their respective performance objectives. If you want to research, go study on what events lead to the Nosler Partition…The Bear Claw…The X bullet…The now defunct Bitterroot Bullet Company who pioneered bonding technology. There is a “why” to those items. That why has not changed.
If you truly want to dig into 223 projectiles, you might be able to google some of the publications that Crane released during the Greatest War on Terror. They did a ton of testing on 855, MK 318/ SOST, Brown Tip (a 70 gr X bullet), and 855 A1. They usually contrasted 77gt SMKs in most tests as it’s the standard projectile in MK 262. You can see all of these in gel if you dig around.
Here’s some dated, but good, baseline.
https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2008/Intl/Roberts.pdf