I could add some personal experience. I applied to over 26 positions, 12 of which were with the DFO and Coast Guard, both of which you would think would be a pretty good transition. I was told in a phone conversation—not in writing—that I should not be applying for jobs above the PM-4 level, because those should be internal hires. That was directly from the director.
No one would put this in writing, but that's what's happening. If you want to transfer your skill set, they're going to be looking internally, 100%.