Guns you want to see made.

[Nyles]

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.