Will these interchange?
Can I use 38super mags in a 9mm 1911?

Thanks guys.

They should fit just fine.

The magazine is longer than the 9mm cartridge, however.

With hardball, probably not a problem.  Some JHPs might not function well, however.

For range use it is worth a try, for any kind of serious use, I would prefer a proper 9mm magazine.

Most of the  .38 Super Gov't and Commander models I have fitted 9mm barrels to over the years worked well with .38 Super magazines, but I didn't try JHPs in all of them.

Maybe, but likely not reliably enough to trust in a fight or match, especially if you are looking for 10-round mags. The 9mm magazines have features to take up the extra front-to-back space (typically either a spacer at the back or a groove at the front). The 9mm 1911 platform is notoriously finicky when it comes to ammo and magazines, so if yours runs with 38 Super mags you have a bit of a unicorn. If you have some 38 Super mags already, then by all means try them but I would NOT buy 38 Super mags in the hope they will run.

For good 9mm 1911 magazines, it is hard to beat Brownells own brand which, in my experience, work great loaded to 10 and are inexpensive (especially in multi-packs or when on sale). IIRC they are made by Metalform.

One last suggestion: Buy a magazine unloading tool from CZ Custom. This simple device makes childsplay of an otherwise near-impossible task.

38 super mags will work with 9mm, as others stated, it will reliability may be compromised depending on ammo and the individual gun.

If you only have a 9mm, simply get 9mm mags.

I used shooting star 38 super mags before the 10 rd 9mm came to market. They only worked with a few bullet profiles.

best to get 9mm mags as the metalforms I was using had no problems with any bullet profile I tried.

Grab the Brownells 9mm 1911 mags. They have worked flawlessly in both of my DW Valors. They are also identical to the mags that came with my blued Valor other than the logo.