Most people don't realize the reason behind the hollow point design.
INITIALLY Its primary design was not to make
a larger hole, although that was a positive by-product of the design function.
In a "handgun Caliber" .............. the hollow point was designed to prevent
over-penetration at close range encounters. Most ballistic experts recognized that a handgun bullet was more likely going to contact its target in a matter of a few feet ..........rather than a few yards......... and to that end they wanted a bullet that would penetrate and stop inside the target exhausting all of its energy inside. What better way to accomplish this goal, than to have the bullet's aero-dynamic shape [ built for flight to the target ]
change causing the bullet to drastically dump off velocity. For the longest time rifle hunting cartridges accomplished this with various "soft point" designs ........... but this method of bullet deformation was not reliable at handgun velocities ......... born was the hollow point for pistol ammo. I am not saying this is when hollow point projectiles were invented -- only that serious design work started because of the above requirements.
Now a handgun bullet [ hollow point ] would expand [reliably ] and cause the projectile to dump all of its terminal velocity into a target only a few feet away without over penetration. A bullet exiting a target is not only dangerous, but a waste of energy [ whether or not that energy plays a significant role in stopping an attacker - that's another thread ]. The Fact that the bullet gets bigger was a welcomed by-product, but not the over riding objective. They could easily design bullets that would flatten out after striking their target .......but it was controlled penetration that the experts were after. 12" minimum seemed to become the standard in the industry.
The hollow point NEXT was required to provide sufficient penetration AND
expansion while absorbing clothing as a "first barrier". So expansion then became a goal of the smart ammo makers, after penetration control was mastered.
Now companies had a platform to sell their ammo ..........and looked for new and exciting ways to draw in the handgunner. So they advertised bigger holes ......... because as we all know BIGGER IS ALWAYS BETTER !
Just remember ........ pistol ammo [ no matter the caliber ] is still pistol ammo.
The differences between high-end products - from the 9mm to the 45 acp is more hype than manstopping fact.
Stay safe -
JF.