Guys, thanks for all the interest in the topic. My original point was that there is a lot of interest in these PCC's and a growing interest in a PCC offered in a more substantial caliber than 9mm. 10mm was what I saw cited pretty often. But it had seemed to me that 10mm or similar caliber would be a bit much for the blowback design of a Ruger PC or similar carbine. So a locked breech, handy carbine offered in an effective PD caliber, well I just seemed to me that just such a thing had been purpose built 70 years ago, and an old concept is new again. I am fortunate enough to have my father's Plainfield M1 Carbine (which runs perfectly), and frankly have been infatuated with it since I was a kid. I hadn't really considered the interchangeably of ammo and mags, or the relative cost of the platforms.
Fact is, though I have not yet reached my 40's (though they are fast approaching) I have what is probably an unreasonable affinity for outmoded technology. I guess I just like blue steel, walnut stocks, 1911s and 16ga shotguns.
I have an AR15 and a poly 9, and they function very well. But, there's the smile factor involved for me. I just get a bigger kick out of those old guns. Kinda like putting a 2018 Honda Accord up against a 1969 Camaro, the Honda will do it better faster and cheaper. But the smile factor dumping the clutch in a 69 SS
I suppose Camaros have points and condensers, carberatur adjustments and will rattle your teeth, and M1 Carbines have parts availability issues, expensive ammo and no ammo compatibility. But if I roll up to my local range with either one, I'd wager I'd leave with a bigger smile on my face