REPOST: Where can I find these coins?

[Questioner]

First off let me apologize by not putting up an image. I spent 15 minutes trying to find this particular coin (not sure if it's a challenge coin) on google. I just saw it on the GM facebook page. Apparently an instructor at Great Lakes IL GM A school has been selling them to the students and it is just an awesome looking coin. I've changed my profile picture to the front image of said coin.

The front is of a shield with the GM skull on it and behind it is the GM cannons. Underneath is a scroll that says defenders of freedom and on the back is a picture of the glass house with the saying Sic Vis Pacem Parabellum, "Navy for tradition, Gunners Mate by choice" and the Navy logo.

Underneath on the back of the forward scroll is one that just says "Navy Gunnery School; Great Lakes IL"

I'm not a Gunner yet nor have I been through boot camp (obviously) but I just want to know where I can get these in case when I do finally achieve the honor of attending GM A school, the instructor selling them is no longer there.
It seems like a lot of Gunners just heard about it like I did when the guy in A school posted the pictures. How common is it for brand new Rating coins to start circulating?

[wraeth]

Sounds like a generic MOS coin. You should be able to find it, or ine like it at the NEX after you graduate.