To this date, I stil don't know why someone hasn't taken the FN5.7 pistol round and started producing rifles for it.
Well, there is the P90, with up to a 16" barrel. Quite the critter to shoot. I was amazed while shooting the shorter, full-auto version, that the red-dot sight never left the target. Really fun to shoot, and I'd guess effective. Never shot anything but targets with it.
Re rimfire alternatives - dang, I just buy & shoot 22 and .17 ammo. Hasn't been a problem getting it, at decent prices, for a couple of years. Made it through the worst of the shortage via a large quantity I'd built up, buying a brick here and there over the years.
Guy
