A new barrel (and maybe a different recoil spring) should be all that's required to do the conversion. .38 Super magazines might work reliably, but I think you'd have to verify that for yourself.

Taurus is going to be releasing their 1911 in 9mm any day now.

I've considered having a 9mm barrel fitted to my Commander shortly after I bought it.  It is a fairly coomon conversation and Super. 38 mags should be reliable enough for practice.   Other wants and needs kept me from doing it.

I've heard that Taurus 1911 barrels are a bit out of spec.  I've also never found a drop-in barely that truely was.

Getting away from the point slightly, if one wanted a 1911 in 9mm, the most efficient way to go about it would be to buy a Browning HP. No, it's not a 1911, but it is another classic Browning design in single action, is doublestack (which takes advantage of the 9mm's capacity) without being bulky, and shoots like a dream. I've never understood the 9mm 1911, unless one is looking for a smaller gun on the 1911 action or one wants a full-size 1911 in 9mm "just because" (which is always a good reason).

However, if one was looking for a 1911 in .38 Super and wanted a 9mm conversion for economic reasons (cheaper training), I say have at it. That's a dandy idea...just don't forget to keep up your practice with .38 Super as well.

Mike

As others have said, properly fit, the 9mm barrel will work fine with a 38 Super slide and be dependable enough for practice.  It may require dedicated 9mm magazines. 

If you are at all interested in reloading, Randy is right about the cost.  Reloading is less much less expensive than buying 9mm in terms of cash outlay if that is your major concern.  The minimum tools required will fit in a shoebox.

You are stuck for time more than cash, you may be better off with a 9mm barrel.  It all depends on your personal calculus. 

I've got a 9mm 1911, but it is an STI with an absurd capacity magazine. I don't think I'd bother with one in single stack.

Well steel pistol's have for lack of a better "soul" which is something that polymer lacks, but that luxury that I can wait for.