Last year I experimented with a straight-walled .30-caliber pistol cartridge that fit in between .32 ACP and .30 Luger called the 7.8 x 19mm. It started because I had a Helwan with a broken locking block that I’d converted to straight-blowback, some .30 Carbine brass and a distinct lack of adult supervision. You can read the start of that journey here. In the end I discovered I had basically duplicated 7.65 x 20mm Longue, an obsolete pre-WW2 French service cartridge.
In the end I got a new 9mm barrel with a good locking block and I side-lined the project, debating whether to line the new barrel and proceed with testing hotter 7.8x19mm loads through the locked-breech system. No Point now, because Federal Premium ammunition has done it for me.
https://tinkertalksguns.com/2022/01/06/ ... cartridge/This really does look for all the world like 7.65 x 20mm, though exact specs are not available at the time of this writing. Federal touts this as the first full-power cartridge designed for civilian self defense. OK, whatever. The idea is you can get more rounds on target faster. Power is comparable to 9 x 19mm, you get a couple more rounds in the magazine. What’s not to like? Yeah, let’s get back to that in a bit.
Expansion and penetration look good too. .30 SC comes in bullet weights ranging from 100-115gr, so it is heavy for caliber (for pistols at least) which gives it a high sectional density. This gives it good penetration even with expanding bullets. The fact that these bullets are lighter than many popular 9mm loads means less muzzle-flip.
Not Much Good Without Something to Shoot it Out of…
You’re in luck there; S&W is chambering the Shield EZ and Shield Plus for this cartridge, and if you really insist on spending ten times as much Nighthawk Custom is offering a gun as well. Seriously, almost ten times as much; the Nighthawk is a skosh over $4000, and you can order it now.
Federal's HST load -
https://www.federalpremium.com/handgun/ ... HST1S.html
They're claiming 1250 fps for a 100 grain JHP from a 4" test barrel. Sounds loud to me.