Which bullet does the 9mm use that .40 S&W and .45 acp can't?

[Mike J]

That's just how Grumpy Old Men Are.
I have always said that you should carry the largest caliber that you can handle proficiently. But take into account that mag capacity and the fact that in a high stress situation you don't shoot as good as you would at the range.
Over twenty years ago a guy named Blackburn was stopped by a Hwy Patrol Officer for a traffic violation. While the Officer was talking to Blackburn, outside of their vehicles, Blackburn pulled a North American 22 revolver from his pocket and shot the Officer one time from about 4 feet away. The Officer pulled his 357 revolver and shot Blackburn 4 or 5 times in the upper body. Blackburn fell to the ground and the Officer took cover behind his vehicle and called for backup and that he had be shot. All of this was caught on the Officer's dash cam. The Officer died. Blackburn is still doing life in prison.
This true story is to remind those that you don't always win the fight even if you have the bigger gun.

I understand that Gunny. There ain't no guarantees. We all make our choices & take our chances. I also understand your position is that you would rather have more ammunition than a slightly larger caliber. I just got another 40. It is a M&P 2.0 40 compact. I really like the low bore axis. I shot it the first time this morning. Perceived recoil is like nothing to me with this pistol. I do need to get some full size magazines to carry for spares.

 

[GunnyUSMC]

I understand that Gunny. There ain't no guarantees. We all make our choices & take our chances. I also your position is that you would rather have more ammunition than a slightly larger caliber. I just got another 40. It is a M&P 2.0 40 compact. I really like the low bore axis. I shot it the first time this morning. Perceived recoil is like nothing to me with this pistol. I do need to get some full size magazines to carry for spares.

I carried the 40 S&W for my first 16 years on my dept. I really like the 40, but nerve damage in my neck and right shoulder, from radiation treatments, has made it hard for me to stay as proficient as I need to be. With the lighter recoil from the 9mm I can average 10 to 15 point higher scores at the range. With the 40, after about 60 rounds it would become difficult to pull the trigger. With the 9mm I don't start to have issues till after 100 rounds.
I still have my Gen 3 Glock 22 that was issued to me in 2012 when my dept. went from S&W to Glocks. I was able to buy it for $298 with three mags when we updated to the Gen 4.
I've been carrying a 17 Gen 4 for about two years now and will have the opportunity to buy it within a year when my dept upgrades to the Gen 5 Glocks.
So don't get me wrong, I like the 40 and see no problem with anyone carrying one.

 

[Mike J]

I understand Gunny. That makes sense.