Also, a semi automatic MP5

I don't think the S&W No.3 frame will accomodate a round as long as the .357. And the old barrel latch definately wouldn't stand up to the pressure, they're not super strong guns.

hk94? Mp10?

Seriously? A .357 Magnum on a break action revolver? The .38 sure.

No, a real MP5, but semi instead of full/burst

Really? Damn.

Well, as you all know new guns don't really excite me much, but I was thinking about some guns that were almcould have been made I wish they had.

Colt 1911 in .41 ACP - JMB was designing a .41 caliber version of the 1902 Auto, but the round was too much for the design, and by the time they figured out the solution the US Army had decided they wanted a .45 so the whole project was abandoned. If they'd kept doing with it and came out with a .41 ACP loaded somewhere near .38 Super levels, that could have been a pretty neat gun.

Colt 1911 in 7.63mm Mauser - Preferably with a tangent sight and attachable stock - basically similar to a Star Model A Pistol Carbine without the extended barrel. Might have sold well in Europe and Asia.

Steyr 1912 in 7.63mm Mauser - Likely have to beef up the design a little, but it sure would be a cool gun. And the 1912 was a good design that might have sold better if it chambered a more common round.

Mass production of the H&K P7M7

Yeah, the length of the cartridge in a top-break gun is limited by the arc it has to travel to open - that's why the Schofield couldn't chamber .45 Colt rounds (and the reproductions had to be redesigned so it could). Same reason that the Brits went to .38 S&W instead of .38 Special when they decided they wanted a .38.

And espescially the barrel-mounted latch on the No.3 was quite weak - if you ever examine when you notice there's not actually all that much holding them together. The frame mounted latch on a Schofield (which is very similar to a Webley stirrup lock) is stronger, but even a Webley can't stand up to .45 ACP pressures, let alone .357 Mag.

Makes sense. I just want a Model 3 chambered in a relatively easy to find cartridge