I don't see why not. Most 9mm 1911 mags are .38super mags blocked off at the back. I'd want to make sure the extractor was good for 9mm, given the .38super is semi-rimmed.
Thing is, what does .38Super do that 9mm+P and 9mm+P+ don't already do?
Caliber: 9mm Luger Plus P
Bullet Wt.: 125gr CORBON Self-Defense JHP
Velocity: 1250fps
Energy: 434ftlbs
Test Barrel Length: 4.0 Inches
Caliber: 38 Super Auto Plus P
Bullet Wt.: 125gr CORBON Self-Defense JHP
Velocity: 1325fps
Energy: 487ftlbs
Test Barrel Length: 5.0 Inches
Caliber: 9x23
Bullet Wt.: 125gr CORBON Self-Defense JHP
Velocity: 1450fps
Energy: 584ftlbs
Test Barrel Length: 5.0 Inches
The above are CorBon numbers. (I didn't see a 9x19+P+ listing). Even allowing for the barrel length difference, the improved velocity and energy at equivalent bullet weights are worth it to me. YMMV.