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I chose the top option, but there are higher levels of proficiency, I suspect. Personally, I've built about 20 ARs now from unassembled parts for myself and others, including scratch-manufacturing parts. I've worked on probably 3 or 4 times that many rifles.
I still don't consider myself any sort of "expert".
The AR15 really is the lego of rifles and can be worked on to varyign levels of proficiency by the everyman.