Glock 21 and Glock 30

[MASTERLAB]

Call me crazy, but...

Does anyone know if you can put a Glock 30 slide on a Glock 21 frame, and vise versa. Do the rails match on the two frames?

[tankton]

Rail width, yes. Locking block, I don't recall . AFAIK, it has the same issue with trying a 17/34 slide on a 19/26 frame.

[5ZS]

Will not work.
The only way to get a 30L, is to grip chop a 21.

No idea why Lone Wolf will not make 30 slides at all.

[MASTERLAB]

What is the reason it will not work?

Is it because of the exposed portion of the slide?
What about having the 30 slide on a 21 frame?

I am actually more interested to see if the rails are the same distance from each other. We know the width is the same, how about length from front to back?