.44 Spl vs Magnum Cylinders in recent production

[Sandman4delta]

To open, this is meant to be a theoretical topic.
I have both Magnums and Specials in configurations that I like.
And of course the disclaimer: It is not wise to shoot a caliber in a gun for which it was not designed.

So, on to the subject...
Through reading and different topics discussed here and elsewhere,
It would seem that S&W used the same components to produce multiple models of N Frames in the more recent era. Makes sense to simplify production if done safely.
Specifically, am I wrong that the cylinder length of the 21-4 Special from early 2000's is the same length as the Magnum cylinder?
I saw a topic about some folks being able to chamber a Magnum in their .44 Specials.
I have checked all of mine and found that none would chamber a Magnum. (whew)
Is the raw part used to produce a .44 Spl the same as to produce a .44 Mag?

Here's the theoretical part:
What would stop a person from reaming out a bit to chamber the Magnum cartridge?
If a person did that, (or maybe installed a Magnum cylinder,
What would be the expected point(s) of failure.
Which parts are actually different in preproduction (steel quality, hardness etc.)?
Could there be someone out there that has abused a 21-4 or similar revolver in that way?

 

[StrawHat]

Not sure about the 44 Special to Magnum conversion but the are more than a few 38/44 Heavy Duty or Outdoorsman revolvers that were recut to handle the 357 S&W Magnum.

Kevin

 

[Sandman4delta]

I don't have a micrometer, but with my caliper I found that my 21-4 and 29-3 cylinders have nominally the same dimensions, (diameter and length).
While my 24-5 heritage has a noticeably shorter length.

 

[SP45]

This conversion was done also with the model 15 to 357 magnum as long as the cartridge length wasn't to long.