Welcome to the forum.
Yes, that's military 9mm brass. You'll have to remove the primer crimp before repriming.
You'll find that it's heavier brass than commercial, meaning the case walls are thicker. It's excellent brass for reloading, once you remove the primer crimp. I've stopped using commercial brass and use military exclusively in 9mm, since I run them rather warm.
You'll also find 9mm with the FC headstamp, for Federal Cartridge. It's also good brass, but not quite as thick walled as the WCC headstamped brass. Those are the two headstamps I've run across in 9mm, but in other calibers you'll see RA for Remington, plus many, many others for World War II and Korean War ammunition.
The other day I found a Lake City headstamped .38 Special case. This was the first one I had seen out of the thousands of rounds of brass in that caliber that I've loaded. Most was marked either WCC, WRA or RA.
As an aside, Federal is owned by Alliant Technologies (ATK), and ATK runs the Lake City Ordinance Plant for the government under contract, but the FC brass is made in the Federal plant.
Hope this helps.
Fred