That is my gun, it started out as a .38spl but if your read the text of that old post you'll see that the frame is the same as the M&P360 and, per S&W, there is no difference in the steel of the .357mags and .38spls, the chambers are just cut to different depths. I know guys that have converted aluminum framed guns with good success but personally I wouldn't do it. Since S&W doesn't chamber them for .357mag, I wouldn't try rechambering one to 9mm.
Since the 9mm conversion subject keeps coming up I'll give an update on it-
I've carried it almost everyday since that post, I have put 750+/- rds of standard 9mm 115gr FMJ through it, plus another 50rds of Federal 9BPLE 115gr JHP +P+, about 50rds of .38 Super, and 15rds of 9x23 Winchester. The gun has functioned perfectly with zero problems and shows no signs of stress or damage. It has proven to be functional and accurate, I qualified with it on our duty pistol course of fire (shooting from 3yds to 25yds) going through 100rds in about 35 minutes. My score was within a few points of what I shoot with my duty gun. The short cartridges and moonclips make reloads a snap.
The only issue I've had with it was that I would get rust on the edges of the cylinder flutes on really hot humid days when carrying in a pocket or ankle holster. I sent the cylinder to Robar and had them coat it with NP3 and haven't had any trouble since.
I've since learned that, like so many things, the conversion is a compromise as there is a minor loss of pressure thanks to the diameter of the chambers and the "freebore" travel in the cylinder.
On the plus side, I;ve found that the .357" bore vs .355" really doesn't mean anything in the real world, that .0002" just isn't the issue some folks seem to think it would be. The bullets engage the rifling and fly true, accuracy is good and there's no keyholing.
If you read that old post you know what I have into the gun, plus the cost of refinishing the cylinder, and it has been money well spent. The gun turned out exactly how I wanted it, it's performance has exceeded my expectations, and 2 1/2 years later I'm still happy with it. It may not be everyone's cup of tea due to cost, caliber, type of work done, or whatever, but it's works great for me.