The problem is as most things semi auto are magazines. If it was a 9mmx45 it might be easier to convert but then you get into 300 whisper/blk territory.
Maybe 10-15 years ago it might have had a chance but today there are better choices.
A more feasible way to go maybe like the 460 rowland just extend the case to 9x20 use more powder ream the chamber to x20 depth then you can increase powder charge and just seat the bullet a bit deeper using the heavier .357 diameter bullets. That way you got a ready supply of magazines and ar lowers adapted to use them
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent