Greg Ellifritz put a post up recently wherein a reader of his blog inquired as to the desirability of toting a specific 10mm load in his CCW piece, namely a 200gr hard cast solid.
We'll overlook the fact that said reader used the phrase "stopping power" in relation to handgun bullets, and note that his choice of a 200gr hard cast solid is emblematic of the state of 10mm ammunition up until recently.
The 10mm Auto cartridge hit the scene in the mid-late Eighties and peaked in popularity in the early Nineties, featuring brief usage by, most notably, the FBI and the Virginia State Police, as well as a longer stint with the Kentucky State Police.
Durability issues with the frame-decocker models ended the flirtation with the round by the Feds and the VSP, and after a decade's use the KSP guns were starting to show wear and tear, and the pistol had been long discontinued by S&W so Kentucky went to the Glock 35.
For many years there were only a handful of CCW/defense type handguns on the market and lack of interest meant that most carry-type loads dated to the late Eighties and early Nineties, in the chambering's heyday. Projectiles like Winchester's Silvertip, Federal Hydra-Shok, and Hornady's XTP were generally excellent performers in bare and clothed gelatin, but lacked features that made for modern barrier-blind (or at least barrier astigmatic) performance.
Then again, as a private citizen I'm not as worried about defeating windshield glass or shooting through plywood with my concealed carry blaster. Were I toting a 10mm, I'd have no issue carrying the 175gr Silvertip, for example, which performs well in tests as well as in real life.
In addition to the classic loadings, there are newer ones out there, thanks to the renewed popularity of the chambering. Rounds such as Speer's Gold Dot, Hornady's Critical Duty, and Federal Punch take advantage of developments in projectile design made since, oh, 1992 or so.
With the newer bullets, I don't know that there's a lot to choose between with .40S&W and 10mm performance. With the older loads, like Hydra-Shok and XTP, I've found that the extra ~100fps bump from the Big Ten turned the heavier 180 and 200 grain loads that could be marginal in the .40 into more reliable expanders that were less likely to glog up and over penetrate.
As far as high-velocity heavy bullet loads, save that stuff for hunting or hiking in bear country, because most of the extra steam's wasted on non-quadrupeds.
