Ok, so I did some investigating today. I don't know how true any of this is, but this is what it came to: A device has to be a registered device on MetroPCS's network in order to be used. The sim is actually registered to a device, unlike using a sim on AT&T or T-Mobile. Since the 925 isn't in the system, it won't work.
I will actually just stick with T-Mobile since they have comparable plans and I can feed my need of switching phones every few months.
I see this comes up on the front page of Google if you search for this specific inquiry, so I hope it helps others.