With no direct federal contracting experience you're unlikely to come in as a GS12, much less a GS13. Every posting I've seen for 12 or above has required the FAC-C or DoD equivalent contracting certification, which you're not eligible for without a minimum of 12 months working in federal contracting.

You could come in as an 11 with a PhD, or a 9 with a masters.

You could potentially negotiate steps, but grade is unlikely.

It wont be as challenging as law school. USACE will be a lot of source selection and pre award contract admin.

Best of luck. It’s a good career track and the hop to a 13 PCO/ACO will be easy. The warranting process is a pain but that’s after the fact.

The 13/14/15 in the 1102 world is usually team lead positions or branch chief positions.

So essentially after you get your GS12, you have a couple of options.

Option 1. Wait for a non supervisory 13 to open up and apply, this is the route if you wish to not be a supervisor.

Option 2. Apply for team lead positions at the 13, this is if you want to dip your toes into supervisory.

So it's basically a decision if you want to be a supervisor or not. My agency(NASA) goes out to a 14 non supervisory, but those are mostly dinosaurs.

You will have to recompete and interview for the position while your 7/9/11/12 usually doesn't require interviews.

P.s: The max promotion potential is the max a supervisor can promote a candidate to. They can not promote just because your a good employee, it goes against competition requirments and would require you to interview again.