Video it and post it, as it would be the first time that anyone has been able to prove your findings! I’m sorry, but the tests have been done thousands of times in much more controlled conditions than your excrement, and they all come to the same conclusion. Fast bullets always expand faster than slow ones. How does a .220 swift or 7 REM mag ever kill game effectively if speed is an issue!
To answer you last question first by using the correct bullet etc and the test I did was with a 7 mm mag.
When I first found this issue in the 80s I asked Sierra and they suggested they were the ones that told me to either aim for shoulder or slow the bullet down!
When I was shooting in Poland with RWS present some of them were using 7mm magnums, the people looking for game were complaining that the bullets were going straight through pigs and the fat was sealing the tiny exit. yet pigs shot with same bullets from 7x64[slower] were leaving blood trail as exit was bigger.
I am no expert on these things, I do not make videos or know how to.,, but i am a realist and I live for hunting. i am in the field 300 days year and I know what works and where etc. There are to many claims made by the so called experts that simply do not live upto scrutiny in the field, because they need to make money.
I used 180 grain bond strikes for very long range hunting and the opened perfectly at long range, in your idea they should explode on contact at close range, yet in reality they come out of game the same size they go in at 20 meters, thats a fact Ive seen with my own eyes.
You only need to think how many times people say the same thing, there must be a reason for it.
The trouble is people use gell etc to prove a point, it creating something that is equal though out.
Look at it this way. If you were to fire a given bullet at a pile of newspapers as some do, they will stop the bullet and it will expand, then fire the same loading at a sheet of news paper! it will not expand as there is not enough resistance for it to expand.
Bullets need the resistance and soft tissue on normal hunting bullets does not give the resistance required at very high speed.
Anyway thats enough of my rambling, either you are like me and accept your own experiences and eyes etc or you believe the sales talk. Your choice not mine, I made mine years ago.