Fake motivational posters abound: 9mm – for those who squat to pee... Why .45? Because they don't make a .46... (although they do make a 50) … 45 – because shooting twice is silly...9mm may expand but 45 never gets any smaller... and more. It was only a few days after the shooting of congresswoman Giffords that I saw someone post that if the psycho had been shooting 45 instead of 9mm, she wouldn't have survived. On the other hand, I've seen ER doctors say "no physician ever saw a gun shot wound victim being wheeled in and said, 'don't worry, it's just 9mm'". And the famous FBI "Handgun Wounding Factors and Effectiveness Survey" study (on Scribd, but other places, too) said there's no such thing as "knock down factor" in handguns, and the three most important considerations are shot placement, shot placement and shot placement.
I recently came across a deal on used Taurus Millenium PT145PRO, my first .45. My only experience with the caliber is that I shot one in my concealed carry class a couple of years ago. So now I have 9mm, 40S&W and .45ACP available to choose from. I posted about a year ago on changing EDC from my Taurus Slim 9mm to the XD Subcompact in 9, noting they were virtually the same size overall, but the XD carried almost twice the number of rounds. It turns out the PT145PRO is virtually the same size as the XD; a tiny bit thicker, and a little longer in the grip. Does it matter? I haven't tried to dress around it. The PT145 is a 10 round magazine (10+1), so less ammo than the XDsc, but more than the Slim.
So far, I've run 200 rounds through the new PT145PRO, to ensure smooth functioning. No problems except for a couple of FTEs in the last 50 rounds. New gun break-in? Dirt from a few hundred rounds? Don't know, but everyone who handles a semi-auto has to know how to clear a malfunction and a couple every few hundred rounds are not an extreme concern. This was ball ammo; I'll have to try some good hollowpoints to make sure they function before I'd commit to that. Two long-time friends have essentially the same gun. One is trouble free, the other had to send it back to Taurus to make it trouble free. Taurus has a lifetime warranty and will not only fix the defective gun, they'll upgrade parts to the latest version (or so I've heard). Will I carry it? Not through the summer.
There is an interesting alternative – that I don't own. Taurus has announced a successor to the PT709 Slim, the PT740 Slim in 40S&W – the same caliber as my Xdm. It turns out the ballistics tables show the 40S&W (once derided as “40 small and weak”) as superior to both the 9 and 45 ACP. Look at the advantage in impact energy of the 40S&W JHPs (155 grain) vs. the 124 grain 9mm and 230 grain .45ACP. This screen capture is from the Federal ballistics program you can download here.
The new PT740 just won the NRA's handgun of the year award, (to roars of derision from Glock Talk fanbois) and the PT709 is credited in some circles as starting the now very hot trend of single stack, slim 9mm pistols for concealed carry, although they certainly were on the market before it. I'm not sure the Kel Tec PF9 was the first, but it was among the first.
Could it be the answer to the perennial question of “9mm or .45?” is “Neither: .40 S&W”??