Pistol cal carbines can weigh in at 6 lbs or less. Also, The variable power of a revolver round makes it versatile. A low power cast bullet load will take small game without destroying too much meat and a more powerful load can take medium and large game if ranges are reasonable. Finally, low pressure, light kicking pistol loads are, in my opinion, a lot more fun to shoot than centerfire rifle rounds.
Jason, you can't juggle the muzzle energy of the rounds like you're suggesting from mild to wild in a semi auto. They rely on the ammo being within a fairly narrow range of power to cycle the gun correctly.
Which brings us back to the good ol' lever action. Because it's manually cycled it doesn't care how mild to wild you load the casings. It's also far from slow. I can point to any number of You Tube videos of ultra fast cowboy action shooters blazing away with lever guns that sound more like a fairly fast semi auto. Of course many will be quick to point out that these guys aren't human and they are shooting mouse fart loads. But even if we allow for "proper" power ammo and provided we desire reasonably well aimed shots the lever action gives up very little to a proper semi auto.
Just yesterday we had a fellow shooting his cowboy action 1873 in my club's monthly Speed Steel match. His times matched or were slightly better than a lot of the folks that were shooting semi auto handguns.
So yes, a semi auto carbine like a JR, Keltec, Beretta and others can pump out rounds fast. But for AIMED fast rounds I'd suggest that the lever is at little or no disadvantage to a semi auto. And granted this leaves the true semi auto guns as a better option for PD. But the focus here seems to be more for hunting and general range shooting.
I must admit that it is very interesting that the Ruger semi auto .357 and .44Mag carbines continue to enjoy a pretty healthy popularity. But I also believe that it's a niche market that is easily satiated with a small production batch run every 5 to 7 years and sent out into the world.
As mentioned already what seems like a natural idea that EVERYONE should like often is only attractive to a small sliver of the market. It's typically a very enthusiastic small sliver I'll grant you. But nonetheless it's not going to make a major producer rich to produce such a firearm in massive quantities.
And I sure as blazes do not see this enthusiastic sliver of the market being able to support the profitable production of yet another few specialty cartridges. Namely your rimless .357 and .44 Mag rounds. Not when there's already so many other options already out there. And not when S&W, Ruger, Coonan, Desert Eagle and likely others I don't know about have shown that the rimmed cartridges can be handled in a semi auto magazines of various types already.
So.... as a fellow enthusiastic sliver portion shooter what would
I like to see?
For me it's not so much a semi auto that limits me to full house magnum power loads and strips away my ability to load mild plinkers and small varmint/game loads.
Instead I'd like to see a short stroke pump action that uses a vertical box magazine of both 5 and 10 round magazine options. 5 rounds for the lightest and most compact hunting carbine and the 10 round option for range time fun. Options would come in all the more popular and somewhat less popular chamberings of .327Federal Magnum/H&RMag, .357Mag, .44Mag and .45Colt. And perhaps in two different size actions to split the recoil strength limits. A "small block" lighter option for up to .357Mag and the "big block" for .44Mag up to 500S&W.
Or if the pump action idea won't give the support needed and keep the weight down I'd be more than willing to go with a short throw bolt action. But one set up in a way that allows for fast bolt handle cycling and shooting where the bolt handle allows for a two or three finger continuous hold on the bolt handle while the middle or ring finger pulls the trigger. A serious "mad minute" style of bolt action setup.
