<snip> I'm sure some people here have done it in the past.
Like these guys? (Warning: Dead critter content)
http://talk.slingshots.com/forums/showthread.php?t=1713http://talk.slingshots.com/forums/showthread.php?t=1837http://talk.slingshots.com/forums/showthread.php?t=2507A lot of these guys use homemade rigs with flat bands made from Therabands instead of commercial tubular bands. Quite a bit heavier draw and projectile weights then what Walmart sells.
With my accuracy, I'd limit my shots to 10-15 yards for a "Bunny size" target.
EDIT:
A historical fact of interest is that cities really only started to grow once agricultural technologies took off. No power and gasoline means no combines, trucks, or other modern machinery. It's going to be hoe and scyth time for most of the population just to grow enough food.