If I was looking for a plinking rifle that I wanted to take with me, I'd get a Browning .22 autoloader, or a Winchester 9422 (they takedown), or a Marlin 39M (they takedown), or perhaps one of the Taurus Winchester '06 repro pumps (they takedown).
If I was looking for a defensive weapon to carry that I could put in firing condition in short order but that was normally disassembled to avoid firearms law hassles, I'd look at a Kel-Tec Sub9 or Sub40 with the grip for the magazine of my choice (Glock, S&W, Beretta -- I'd choose Glock just because there's so many mags out there). It takes about a second to unfold the gun, another second to slap a mag in and cycle the action, and you're up and running.
Firing .40 S&W/180gr hollow points out of a 16" rifle barrel will give you better-than-10mm performance with almost no recoil. Firing 9mm/124gr hollow points out of a 16" rifle barrel will give you better than +P+ performance and absolutely no recoil. If your main concern is two-legged varmints then the Kel-Tec is a good choice... and no, I would NOT get a single-shot for self-defense unless you are good enough to get all of the bad guys to stand in line and you never miss.
Yes, the Kel-Tec costs more than a Handi-Rifle. I, for one, don't try to save money on defensive firearms, medical care, climbing rope, and other life-saving equipment.