Why heavier 9mm rounds like 147 gr feel softer shooting than 115 gr?

[SteelonSteel]

An old discussion but this popped up in my ammo research.

 

My two bits on the topic.....

 

it is as much about perception and shooter interface with the firearm with the ammo.  

 

Yes all of the laws of physics apply, it never goes away

 

But I think the individual perception is a factor.

 

Me I like slower slide speed. I come from .45 ACP and 1911s, then in uniform carried a Glock 22 with various 180s.   Anytime I shot lighter ammo that was full powder I had to mentally readjust.  I was gifted a half a case of Remington .40 165 JHP duty ammo along with some .308 match ammo from a Border Patrol Agent friend of mine.  Holy moly was that Remington ammo loaded hot.  It was the most dramatic difference in felt recoil in a hand gun that I ever felt.  At the time my agency duty ammo was the older Federal Hydro shok 180s.   The BorderPatrol ammo were rockets in comparison.

 

It cycled the slide with a most violent speed, bottoming out the Glock 22 recoil spring consistently.  IIRC they were carrying the Beretta 96 DA at the time. 

 

Anyways my theory is the slide speed gets inside your OODA loop, unsettling the shooter.  Noise, front sight forced off the target, perhaps your grip on the gun challenged by recoil.   To me the mind is like a cameras recoding at a certain film rate.   If the action outstrips the “camera” of the brain then you get a disconnect.  It can be addressed with repetition training until it becomes your new normal and the “camera” frame rate is adjusted.

 

I know it sounds wacky but people focus on the physics of the matter and set the shooter’s interface aside to quickly.