What is stopping power is a can of worms.
The problem with most tests is that they are on non living things. Shooting buster to see if he falls down does not mimic hydrostatic shock that occurs to a living creature. Dr. La Guaurde, I think I got his name right, wrote a book on bullet woods. At the turn of the century. The 20th century. He also was involved with picking cartridges for the US military in the same time frame. The new rounds were called "subcaliber" rounds because they were small compared to the .45,.50,65 caliber bullets used in the US Civil War.
There were a few things noticed in the Spanish American war regarding US soldiers hit with the Mauser subcaliber but high velocity bullets. The wounds were much cleaner since the hole was much smaller so there was less infection. Sometimes the exit wound was a problem but often the bullet went in and out. Very little dirt and clothing was brought into the would either which helped. Compared to wounds from the larger, heavier bullets the subcalibers where much easier to treat. Many soldiers were also paralyzed by the smaller but faster bullets but recovered after a time. The paralysis was due to the shock of the bullets on soft tissue that affect the CNS.
Shooting a dummy might prove that given round can't knock down a dummy. But it does not prove that the same round hitting a live person/animal won't cause enough trauma to drop the person.
I saw an interview about a US General who was a LT in Viet Nam. He got in a firefight with the NVA. He had a an M16. An NVA soldier popped up. He shot the soldier who fell. Another one popped up, was shot and he to fell. This happened two or three times. Obviously the M16 stopped those solders. They dropped. The US LT did not.
But the story ain't over....
Another soldier popped up, was shot and dropped. But he popped back up.
He was mad. He was shot and dropped again. This might have have happened one more time before he stayed down.
So, same shooter, same weapon, same distances but different results. Shot placement may have been a factor but they ALL dropped and stayed down. Eventually.
The US LT was not knocked down by the recoil of the M16 but the bullet did put down the NVA soldiers.
But the story ain't over.
The US LT became a general. The NVA soldier that was shot and kept getting up was also an LT. He survived being shot and eventually made general. Somehow the two generals realized that they were the the two LTs from decades before and met.
The video I saw had them talking about how the felt/perceived the firefight.
Strange story.
Regarding the power of different bullets I can't remember the formula any more but they are in loading manuals and I'm sure published on the Internet. The higher the velocity and bullet weight for a given cartridge the more "power" they have. How that "power" translates into stopping ability is ANOTHER argument/discussion.
Later,
Dan
