Unfortunately, even though the number of 1911 owners out there seems to be growing all the time, market studies showed that only a very small percentage were interested in a companion carbine. The 1911 really isn't a field gun and it's still a pistol cartridge with a small amount of powder so it's unable to take advantage of the longer barrel to any significant extent. Just like the 9mm and .40 S&W you only pick up about 10 to 15% in velocity using the equivalent load from a handgun. The L.E. folks that wanted them, wanted them to increase the range of the handgun from the standard 25 yds out to about 60 yds and that was accomplished with the longer sight radius. The big three ammo makers only make ammunition in these pistol calibers to be stable to 50 yds, beyond that it's a crapshoot. The barrels are capable of excellent accuracy and a number of handloaders have told me that with judicious handloading they've managed to get 3" 100 yd groups. I believe them because the barrels themselves are capable of much better than that. I really doubt that you would ever see a return of the PC Carbine as it was expensive to build back then and would be even moreso now. The tooling investment required for the stock alone way back when was over $200,000 not even including the cost of the changes to the bolt, etc. tooling. The gun was built basically per DoD specs and you could throw it across the room and bounce it off a concrete floor and it would come up shooting. It was built to the same specs as a military battle rifle. Ruger only has one operating foundry anymore as everything is going to MiMed parts as the metallurgy improves and I really can't see them buying a whole set of new tooling for a gun that merely filled a niche market, which is no longer there. We looked at a number of different calibers for the gun, some of which would have really surprised you, but the market just wasn't there to support it. Maybe 10 years from now such a thing would be in vogue, but not today. The few good used ones out there are bringing quite a premium. Where were these folks when we could have used them to keep the sales at a profitable level so we could have expanded the line ? Seems nobody wants anything unless they can't have it anymore. The L.E. folks bought them in good numbers for few years and then went back to shotguns and M16s. The commercial market just wasn't there to support it. It's really a damned good gun for its intended purpose, urban L.E., but not much else. You want to pay to plink with 9mm, .40 S&W or .45 ACP ? Most folks out there can't afford to do that when .22s are dirt cheap and the pop can still jumps around. One comment on the .45 prototypes as I really can't talk about it even now, due to the low pressure and heavy bullet of the .45, the recoil was a gentle push instead of a jolt. A real sweetheart. I tried to get one of the prototypes when I retired, but it was a no-go all the way from the top down.