Urban legend. I instructed some Boy Scouts a couple of weeks ago and the average age was thirteen. With full house loads they were only getting a two inch muzzle flip and hitting or coming darn close. There was only one boy that was having trouble and I noticed he didn't listen to a thing I said.
If one is an energy junky, and a surprising number .45 ACP afficianados are, then take a good hard look at a 10mm auto. Even those of you who love the high velocity, high energy and lightweight .45 rounds need to look at the numbers the 10mm puts up. Certainly the .45 ACP 165gr JHP from Cor Bon is a screaming hot round, with lots of penned up energy to dump into the bad guy. 577 foot pounds of energy is impressive indeed, however, the 10mm wins the energy battle. The .45 ACP has but one loading, the 165gr, that reaches these energy levels, and about three different makers of this loading. With the 10mm, fully 6 loads (and there are more out there!) in four different bullet weights can be chronographed to BEAT the energy levels of the 165gr .45 ACP loads by at least 20 foot pounds (some by substantially more). And these loads give a wide range of bullet weights, from the screaming hot 150gr loads, to the hard pounding 180gr Cor Bon. If you’re into light loads that create big stretch cavities you should be looking at the 10mm, not the .45 ACP or the .40 S&W or even the .357 magnum!
Concerning momentum, many 10mm loads beat the .45 here too. Momentum basically aids in penetration, so rounds with high momentum numbers should get good penetration, provided that they don’t expand too quickly, like the 165gr .45 ACP loadings would. A 230gr .45 ACP from Cor Bon has the highest momentum of that caliber (keep in mind this is a +p load). The run-of-the-mill 230gr has a momentum factor almost 8.3% less! Yet, the 10mm has half a dozen loads which meet or exceed those figures. If you like good penetration potential, why not shoot a 10?
Another area where the 10mm beats the .45 ACP, the 9mm, .40 S&W, .357 magnum or any other cartridge is in the department of bullet weight variety. The 10mm has bullets for defensive use alone in weights of 135, 150, 155, 165, 170, 175, 180 and 200 grains. That’s eight weights! Plus the 190gr, and 220gr weights which are NON-JHP and for other shooting applications. The .45 ACP has 165, 185, 200 & 230 grains – four different weights. 9mm has 90, 115, 124, 125, 127,130, 135 & 147 – that’s eight different weights, but I’m being nice by separating out the 124, 125 and 127gr loads. .40 S&W has weights of 135, 150, 155, 165 & 180, that’s five different weights. .357 magnum has 110, 125, 140, 145, 158 & 180.
Furthermore, only the lighter weight .45 ACP loads are going to open up in the enemy with any reliability. This problem is compounded in the short barrel .45s. If someobody has meat, and big phone books to soak, and old clothes to put over this stuff, you'll discover that .45s work well in all bullet weights out of a five inch barrel. But shorten it to Glock 30/36 length, and the heavier bullets don’t want to expand. Some of the biggest loser bullets you'll find coming out of a Glock 30 are some of the most respected in the .45 crowd. WIth respect to the 230gr crowd: Federal Hydra-Shok barely expands, Federal JHP Hi-Shok doesn’t expand; 200 gr. +P Pro Load (a Gold Dot HP bullet) shows minimal expansion, and could prove to be a big disappointment. 185gr Remington Golden Sabre opens a bit, but shoots the unexpanded core forward, leaving the jacket behind. But the full power 10mm loads are all generating upwards of 1200 fps, well above the expansion threshold for most any decent hollow point. Perhaps only the .357 magnum achieves such results, and the new .357 SIG, but then one goes back to dealing with lighter bullets, and lower momentums.
Chuck Taylor said in his excellent 1997 Combat Handgunnery book, on page 79, that the 10mm "is uncontrollable, exhibits excessive muzzle flash/blast and demonstrates massive over penetration". Granted certain loads do penetrate excessively, but there are so many good 10mm loads, in so many different loadings and bullet weights, that plenty of good loads are available. Admittedly some 10 loads flash and blast a lot, although Cor Bon’s stuff doesn't flash much at all. Concerning the "uncontrollability" factor, people can shoot IDPA, IPSC matches using reloads having similar velocities to self-defense ammunition - this load is a 180gr FMJ-TC, over a charge of around 9.3gr of 800x - usually is sufficient to obtain 1150 fps. That’ll yeild momentum figures 4.6% below the 230gr .45ACP CorBon (.45 ACP 200 gr+p loadi). It would appear that this round can be controlled. This round is quite controllable with practice, something military types should be doing anyway.
Now, the only thing I can't decide is S&W 1076, GLock 29, or Tanfranglio? ONE thing for certain, is that with a ten a double tap most likely won't be necessary (a double tap being like emphasis in italics). Whereas, a 9mm, such as the likes of a SIG-Sauer P-299 (shooting .357 SIG rounds), most often will and require italicised bolding and an exclamation point (head shot) for punctuation.