I’ve often wondered why a 357 mag semi-auto ‘light rifle’/carbine hasn’t been attempted. Ruger’s Deerstalker appears to have a cult following.

Absent that, I’d take a slim and handy 357 take-down lever gun.

Hard to beat cheap and available 9mm, 22lr 40sw (previously) and lever action covers most of the rimmed magnum rounds. While a lot of cartridges have a lot of interesting potential the combination of laws, inertia, and availability/popularity will likely keep things fairly close to the status quo for a long while.

Neat, slightly disheartening but goes to show there is always more to learn. So 40 is probably the upper limit for affordable options.

I had found this guy before. He says blow back won’t work:
Our Sig builds are gas operated and take a customized 6.8 SPC BCG and custom Gas system. These are NOT blow back barrels that can be swapped on to your 9mm lower. This makes the build much more expensive than just a barrel swap. Lead times are now down to 1-2 months!!!!

There is a reason you can’t find 357 Sig Blow Back barrels any more: They Blow Up! They cause case head separations and can damage you and your upper.
https://thearguy.com/news/357-sig-barrels-and-uppers

The problem is no one makes carbines for it. I think people tried to, and they had problems with it.

Stigma is a a funny thing. It may keep rural gun owners away from various incarnations of wannabe smg options and in decades past pistols. For the built up areas full sized rifles are often ignored because of the hassle of finding places to shoot them but realistically the stigma is on owning guns at all so those that do tend to more go along the fuck it I will own and use it just to piss you off mindset. Personally I want to see more development in this in between of large pistol but not quite intermediate rifle as I think many of the lessons learned can transfer to other classes of firearms/powder/bullet construction etc

Older and somewhat dated data but don’t have any problem believing the liberty claimed velocity http://ballisticsbytheinch.com/10mm.html

http://ballisticsbytheinch.com/357sig.html Sig does fine I would probably call it around 10 inches but whatever works. 9…… I would like to see some of the 50-68 grain loadings chronoed but yeah not a huge jump for anything I have seen. I think tok is a tenth of an inch longer than 10 so might be workable depending on mag/grip thickness and construction.