I wouldn't expect S&W to bring back the all metal 3rd Gens unless they decide to resurrect them as "Classic Line" guns.
S&W's main customer base for semi autos isn't the civilian market, it's the LE market. In that market, the lowest bid that meets the spec is going to get the contract. That's not all metal firearms with lots of machining required.
Could they do it? Yes, I think so. As long as they still have the dies for the forge and the programming for the CNC milling machines, they can do it.
They won't though, because those machines are tied up making the slides for the polymer framed guns, machining the slides for 1911 pattern guns, and of course machining the frame for revolvers.
Oh, I almost forgot AR pattern rifles. For both civilian and LE markets. They sell lots of those, I'm sure.
Revolvers aren't used by LE agencies any longer, but there is a big civilian market for them and the market is bigger than for the 3rd Gen guns.
That doesn't even count non firearms parts they make for other companies. Last time I was there in 2012 they were making engine parts for Harley and plumbing fittings for some other company.
Anything to keep that equipment running.
Well, apparently except 3rd Gen guns.
