Has anyone had any kind of luck with using their 5- or 10-point preference for Federal hiring?

It takes a while to get into the system, plus it favors civilian education as well. On top of that a lot of the jobs are only open to people already within the system. GS employment is definitely set up to promote from within.

I think the problem most vets have is they apply for the job they think they should get, or that they think most matches their skill set. For a lot of people, you have to apply to the lowest GS position possible and then work your way up by applying to new jobs.

Good luck

Yes, I have had plenty of luck getting hired with my 10 point preference. If you aren't getting past the hiring manager this means there is something flagging you before you are even referred to HR to schedule an interview. This could be documentation, lack thereof, poor resume, date gaps in employment, lack of documented skills for respective position. These are the things that get weeded out before prospects are referred to HR and your veteran preference doesn't even get looked at during this portion because they are looking for basic requirements needed by all applicants.

I was a senior hiring manager for many years. Most don't understand what veterans preference actually does. BTW hiring managers won't call because it isn't their job. The HR rep handling the action does the up and down lifting. VP increases the possibility in moving an applicant from "qualified" to "highly qualified". You have to collectively score more than whatever the cut off to wind up in the group. So if 3-5 candidates have a higher score than you in the highly qualified group, you won't be with them if there is a breakpoint. There are a lot of Series VP won't apply to; most of them being the professional series like engineers, doctors, scientists, etc. HR types will have to weigh in on more details because hiring managers only receive a "Cert" from HR that lists the applicants by category. That's the cover sheet for the resumes. Evaluations and selections are made according to a "Hiring Plan". It basically is a weighted score sheet that has values for the resume and interview. So if I read your synopsis correctly, that tells me you either never showed up on a Cert for the hiring manager, or you were in the qualified group. Hiring managers must exhaust all highly qualifieds before moving to the qualifieds.
All that said, of the Vets I saw on a Cert and then interviewed, most didn't pass muster. Main reason was poor communications skills. Other reasons included ghost writing and resume (padded) not matching the interview. In general, I recommend development positions like Career Ladders that bring you on board and train you up as you go. We hired many Vets that way in the GS-7/9/11 range, mostly as Contract Specialists. You do need to meet a degree requirement for that.