Building a Boomershooter
I briefly flirted with the idea of putting together something based on the AR platform. As it turned out I'm glad I didn't; I'm not very familiar with that platform and trying to learn it rather than an already-familiar bolt-action would have probably interfered with actually learning to shoot accurately. I may try it for a future event, though -- but I'll make sure I have a lot of time for familiarization first.