SS Contender w/16.25" barrel, synthetic furniture, fire sights.
TC Hotshot, has a 19" barrel and peep sights.
Rossi .22 Singleshot.
Marlin 39 Mountie breaks down shorter barrel.
Taurus 62 pump - slam fire .22 breaks down
Taurus 63 semi - similar to Winchester or Browning models, breaks down, loads through stock.
.22 in a BOB is for hunting, probably not defense, so one accurate shot is preferred to high capacity rapid fire to my thinking. No optics, iron sights only - it's in a pack, scope will lose zero in those conditions. If your relying on your pack rifle, you're probably hungry and hunting different as in stalking and moving as close as possible to ensure a good shot ... maybe 50 yds or less for me. At that point a long barreled pistol gets attractive for me as I've shot smallbore silhouette with a pistol and it's very doable, and you don't have to break it down.