Originally Posted by Jim Watson
No, it has not been done. It could be done but...
A lot of 9mm hardball is pretty pointy, and a straight case pistol cartridge in a tubular magazine is about guaranteed to put bullet noses against primers.
Ed Harris once had a .44 Marlin converted to .45 ACP but would not shoot hardball in it, even one at a time to chronograph, didn't want to give people funny ideas that might lead to a gangfire.
I was kind of assuming that A)the round ball wouldn't be any pointy-er than many .30-'30 loads and B)the 9x19 in a rifle wouldn't generate enough recoil to be worried about it. But, now that you mention it, due to the case profile of the .30-'30 I suppose the noses don't line up perfectly with the primers.
Regarding ballistic increases, I think most that've responded are considering factory ammo, only. I'm pretty certain that with slower powders one could cook up a handload that would benefit from a longer barrel; on the other hand, such loads wouldn't work well (or may even be dangerous) in a pistol - so my thought about a pairing of companion handgun/rifle 9's wouldn't work well anyway. Well, that's brainstorming for you, doesn't always pan out.
Thanks for the replies!