I just received an e-newsletter from Firearms News which they send maybe once a week if you're a subscriber. Right up front, let me apologize for not providing a link. I'm a lousy linker--hard to be good at everything--so you might have to do a little work to find the article about the new Federal .30 Super Carry.
It is discussed at length by 3 "noted firearms experts" and they make lots of interesting observations. It seems that the bullet diameter is smaller than a 9mm but designed to expand, whereas they state that most commonly used handgun rounds utilized for defense were originally designed with FMJ projectiles, and that the JHPs were then designed to meet defensive needs. To me this is kind of a six-of-one half-dozen-of-the-other presentation, as it's if they work or not would seem to be what counts.
They all seem to agree that it is far superior to the .32 ACP and .380 ACP, but comes up about even with the 9mm Parabellum (Luger). The smaller diameter bullet is said to be an advantage in that a couple more rounds can be designed into a magazine, but I'm kind of wondering if 17-19 rounds of 9mm isn't already enough?
I thought this especially interesting in view of the recent thread about "What will replace the 9mm?" Perhaps this is it, but I have my doubts. One thing's for sure, it will be all over the gun magazines in the next couple of months, and you can make up your own mind. Both pistols chambered for the new cartridge, and the ammo will be scarce and expensive for awhile.
DG