I've thought for some time that a pistol caliber in a rifle/carbine would be a great seller; especially if it used the same magazines as a pistol.
I suspect that a lot of the reason for the on-again off-again success of handgun-caliber carbines is subjective, emotional processing rather than objective, mathematical processing. The most common argument against them that I encounter is "if you're going to carry a carbine, you may as well carry one that has more power", and that's certainly a valid consideration. But folks who use that argument lose all credibility when they pick an AR over an AK, or carry an AR in 5.56 rather than in 6.8SPC or such. I have to ask their own question back to them - "if you're carrying that much gun, why carry one with that much less power...?" Not knocking the 5.56 - it's my personal primary carbine caliber. Just pointing out the undeniable hypocrisy of most who claim that position. :dizzy:
Many people decry a .357 magnum carbine as inadequate and inhumane for deer, yet few will say the same about a .44 magnum handgun. Since the two are equal power-wise and the .357 carbine wins hands-down in the field-accuracy and shootability categories, I have to assume it's simple, pure ignorance on their part. Because if it's not a matter of ignorance, the only other possibility is that it's intentional hypocrisy.
Similarly, a .44 magnum levergun will equal a .454 casull handgun power-wise; yes, really. This isn't something I once read somewhere on the internet - it's something I've confirmed with my guns and my chronograph.
Same reasoning (imo, anyway) that people bash the soft-shooting little .30 carbine - they seem to equate "lack of shooter trauma" with "lack of power". Yet even the much-maligned M1 carbine is right in .44 magnum handgun territory power-wise. And anyone who contends that .44-magnum power isn't adequate for personal defense is someone whose knowledge, logic, or motives I simply can't trust.
With autopistol calibers, the gain from carbine barrels isn't as stark as with the magnum-handgun calibers, but the fact is a 9mm carbine loaded properly will easily exceed a .357 magnum handgun for power. And a .40S&W carbine will do even better, pushing 135-grain corbons at 1675 fps, 155-grainers to 1500, and DoubleTap 180's to 1400 fps. IE, 775 to 825 ft/lbs of energy; right at .41magnum power levels. Problem for a lot of people seems to be that those numbers are coming from such a soft-shooting gun, that people dismiss it off-hand.
In the spirit of full disclosure, the .40 S&W numbers are ones that I've not personally confirmed. But they're consistently reported enough, and in line enough with ones that I have personally confirmed, that I have no trouble believing them.
{edit - wish I had some numbers on .357 sig from a carbine, but I don't shoot that caliber and haven't read enough reviews & tests to have anything worth saying on the subject. But based on the little I have read on it - largely at ballistics by the inch - it 'should' be a real sizzler from a carbine barrel...}