Sean H
A .17cal, .22cal should work for long distances but for short use a 20 gauge or 12 gauge. O and try deer hunting thats where the fun is at.

JonnyK
Look at Gamo air rifles. I've had a hunter 220 for years and it shoots great. As for hunting with it, I wouldn't shoot anything larger than a squirrel and would attempt to shoot anything over 30 yards.

Zombie Survival Expert
I hear beemans are good.

J Kirsch
Jackrabbit takes 8 ft-lbs of impact energy. cottontail rabbit takes 5 ft-lbs of impact energy.(1) Pretty much any of the hunting air-rifles (pcp, spring-piston, multi-pump pneumatic), even the low power (8-12 ft-lb muzzle energy) rifles, will have enough power to hunt cottontail rabbits at 20-30 yards (more powerful guns will stretch that to 40 and 50 yards, though 50 yards is probably too far for .177 caliber pellets to deliver acceptable accuracy in most shooters hands). Its jackrabbits that will limit your choices, especially in .177 caliber. In multipump guns, you'll be limited to the Benjamin 397 and fairly close ranges (20-30 yards) though that goes up to 30 yards for cottontails. The Crosman 2100 has just over 9 ft-lbs of muzzle energy (enough to kill rabbits out to 25-30 yards), but at 20-30 yards, that's not enough to be sure of humane kills on jackrabbits. The Daisy 880, Daisy 901, Crosman 660, and Crosman 760 have less power than the Crosman 2100 and aren't viable choices for jackrabbits, though they will work on cottontail rabbits at close range (20 yards or so) In spring piston guns, any of the magnum spring-piston rifles (guns claiming 900-1000 fps (or more) with .177 caliber pellets) would work with headshots. That includes the RWS 34, the Gamo Big Cat, the Gamo CFX, the Beeman R2, the Beeman RS1, the Beeman HW77 MKII, the Crosman Phantom... If cost is an issue, your best chance of finding an affordable rifle is probably a spring piston gun. In PCP guns, pretty much any of the guns available will work since almost all PCP guns are powerhouses. The Benjamin Discovery at less than $400 would be a good choice if cost is an issue. If cost isn't an issue, then you could add the Airforce Condor, Airforce Talon, Evanix Hunting Master AR6 / AR4, Sumatra 2500, or Webley Spectre Mark 2 .177 caliber rifles to your list of options. Honestly, given that you're hunting jackrabbits and will probably be doing so at longer ranges (30-40 yards depending on how skittish the rabbits are), I'd recommend you take a look at a .22 caliber rifle. It really is a better caliber for hunting larger small game animals because the gun/pellet combination delivers more energy from the same/similar model guns due to the heavier pellets; and the pellets will retain more of that energy at longer ranges (again due to the heavier pellets). Just as there are plenty of magnum spring piston guns and PCP guns available in .177 caliber, there are a lot of .22 spring piston and PCP guns available in .22 caliber. Almost all the PCP guns I mentioned have .22 caliber versions, some of which approach 50-60 ft-lbs of muzzle energy (enough power to hunt jackrabbits beyond 50 yards). Even .22 caliber versions of spring guns like the RWS 34 or RWS 350 which won't match the power levels of a PCP should have enough power for jackrabbits out to 30-40 yards (and beyond) with proper shot placement and will benefit from the heavier pellets available at longer ranges. As always when hunting with airguns, shot placement is key and you shouldn't take shots beyond the distance you feel comfortable taking headshots at. Additionally, before you go hunting, make sure it is legal to shoot small game with an air-rifle in your state/province/shire/etc... by checking your local hunting regulations since not all areas allow hunting with airguns.

j c
I would get a gamo. like any gamo hunter, a gamo whisper, or a gamo shadow sport. Another good brand is a crossman. try for a phantom, or summit. These are all .177cals and they can kill a cotton tail or jack rabbit for sure.I have a shadow sport and kill rabbits all the time. but i would recommend a gamo.