If I were a betting man and I had someone that would take the bet, I would lay down green cash money that Ruger never makes (nor even comes CLOSE to making) an SR10mm.
I will say, however, that I'd be happy to lose my bet money if Ruger would do it. I'm a 10mm aficionado and I'd LOVE to see Ruger giving a nod to the cartridge.
I know precious little about the SR series of pistols. I have shot the SR9 full size once and it was fine, but nothing I remember of much significance. I look forward to the next SR centerfire I get the chance to shoot a bit and get to know better.
Since day one, handguns have been visceral experiences for me. I own a couple ugly guns (because they serve a role for me) but I've always been drawn to attractive handguns. I've never found polymer handguns to be any manner of attractive, in any well, really. But since the first release, I have always though the SR series is perhaps the best looking of all the tupperware on the market.
Doesn't mean much, really, just how I see it. I think they look pretty darn attractive for what is (in my opinion) a horribly ugly genre of handguns.
Forget a 10mm being related in any way to an SR40. If they actually built a 10 in the SR series, they'd do it properly--by drilling a smaller hole in a .45 cal barrel and use the .45 cal frame size and slide.
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.