I use the CCI Quiets rated at 45 foot pounds/...or 710 FPS with a full 40 grain RN. I shoot them out of my 10/22 18.5 inch barrel.
I get them at my gun show for about 37 dollars a brick-(500), though I've seen much higher prices per 50 on the internet.
They seem to do the job quite well, though I keep my shots under 40 yards for the fact that my groups tend to open up rapidly beyond that range with my semi-auto carbine.
All squirrels that I've shot were between 25-35 yards. Majority of shots have been head/ neck area shots, and only one shot was needed.
I was a bit taken by surprise after hearing the bullet thwack against the squirrels head on my first time out with the Quiets. The hit was significantly louder than my rifles muzzle report. Sounded like a minature grenade had set off.
For jack rabbits I'd recommend minimags because it's very hard to get under 70 yards in on them. They have extremely good hearing and smell so they are quite the challenge and often require long accurate heart lung shots.
I had one experience where a jack was grazing early dawn in some brush about 30 yards from my porch, with the Quiet I aimed for its head while its back was towards me and quickly squeezed off a shot before the thing noticed me or turned. The bullet had landed a bit lower and clipped its spine. Thing jumped high in the air landed on its side and sorta convulsed while squeeling. I ran over, stepped on it's upper chest, then put final shot to the top of its head. This experience showed me that shot placement is paramount and that anything larger than a squirrel- should remind me to consider more power and accuracy.
For squirrels though, this is one great/ low report round- especially if you own a long barreled bolt action .22lr rifle. It would work for jack rabbit 35 yards and under but placement is critical. Ya won't get many chances at those distances. I wouldn't recommend it for distances beyond 40-50 yards depending on the accuracy of the firearm.