Why the resurgence of the 10mm?:
1) a lot of people want something "new", even if it is only new to them
2) some people have decided that the .45 is not quite enough and the 10mm is quite a bit more than the .45
3) there is always someone that wants the "biggest, meanest" what-ever, but can't handle the .454 Casul.
10mm is only 10mm, or .40 caliber and allows for high capacity in small frames.
It is only slightly more to control than the popular .40S&W while having significantly more energy and flatter trajectory.
It allows a much larger variation in bullet weights and velocity. Any loading that would work in .40S&W can be used, and many much more powerful can be used.
.357 Magnum was the gold standard for a long time, the 10mm is basicly the .357 in an auto. (The .357 sig is not.)
and 4) does not want to pay for a Desert Eagle.
The Desert Eagle is a massive hunk of metal. More suited to a day at the range or in a movie than in real life.
It does chamber powerful cartridges, but they take up a lot of space, and create a grip that is far too large. In a revolver they are fine, in an auto not so much.
The 10mm is however chambered even in some very portable packages suitable for concealed carry. There is the 10mm EAA Witness/Tanfoglio, and the Glock 29.
Arguably the Glock 29 is the better of them because it is 6.77 inches overall, yet has a 3.78 inch barrel, while the Tanfoglio/EAA Witness are close to 7.5 inches long yet only have a 3.6 and 3.66 inch barrel. That means it gets more energy out of the cartridge in a smaller platform. It also has higher capacity.
The vertical length of the G29 is also only about 4", much less than the others (though many add an extension, which itself can add +1 or +2 rounds.)
There is also a number of other compact firearms that can be converted to 10mm Auto which can make excellent defensive or hunting firearms (listing is pointless as they are too numerous).
If you consider full service size firearms there is many in 10mm too numerous to list, with both the potent cartridge and high capacty.
Any well built robust .45ACP chambered firearm can be converted. A robust steel .45 that uses doublestack magazines can be converted, and will hold quite a few of the more potent 10mm rounds which require less space. (Be careful with some of those built to just barely handle the .45ACP as they will not hold up as well. Extra slim models in most materials or most .45ACP polymers for example are not a great starting point (though the Glocks in .45ACP were actualy built originaly for the 10mm.)
A change in extractors, barrels, and springs and you can make any wonderful well built .45ACP firearm a reliable 10mm Auto with even higher capacity. The double stack models really gain a lot of capacity over the .45ACP.
The 10mm is a realistic auto cartridge for defensive firearms that will actualy be carried. Most calibers the Desert Eagle is chambered in are not. They are good calibers in the revolvers they were designed for, where cartridge length has no impact on the grip size.
Part of a cartridge being suitable is the platform making it to the fight, or to the hunt etc. The Desert Eagle is not going to make it there in most cases, and if it is a situation in the home you are better off with a more potent long arm.
Time between follow up shots must also be considered. The 10mm is a nice compromise between individual round capability and follow up shots.
.357 Magnum in an autoloader.
