There's really no point in producing a 'shorty' .410 for use in .45 Colt cylinders.
The problem is that you need to leave enough room in the cylinder to allow for a roll crimp to unroll, or a star crimp to unfold. That means you're pretty much right back at the standard length of a .45 Colt case. So.... why not just use a .45 Colt case and a shot capsule to begin with?
Now, if the goal is to have a higher shot payload than is achievable with shot capsules... you have to get a little more involved in the process.
.444 Marlin cases are commonly used by .45 Colt shot shell loaders, as the basis for 'necked' shot shells like those I load for my .44 Mag (though, I use .303 British, .30-40 Krag, or .220 Swift cases).
(Both unmodified cases started as .303 British, but one has been fire-formed to .30-40 Krag.)
The cartridges laying down, and the cartridge in the center are my .44 Mag shot shells. With an appropriate fiber-wad or nitro-card, I can fit just over 1/2 oz of shot. In contrast, .44 Mag shot capsules barely hold 1/4 oz.
Where I have to put a fair amount of work into thinning and turning the rims of the .303/.30-40 cases; .45 Colt shooters don't have to do so with .444 cases.
It's simply a matter of: trim, form the neck, load, and shoot.
With light loads, you'll never have to size the cases again.
With moderate to hot loads, the shoulder will have to be bumped back when reloaded.
Overly-hot loads may lockup the cylinder, though, by pushing the case head hard against the revolver's frame.
The only good way to achieve easy shot shell-to-metallic cartridge interchangeability, is to use a rifle with an appropriate throat, use a revolver with a longer cylinder (a la Taurus Judge), or go to a cartridge that uses a heeled bullet (so there's no transition to bore diameter to cause a constriction). ...or a combination of those options.