The best and most accurate rabbit rifle I ever used was a Ruger 77 in .22 Mag rimfire. It was just excellent in every way, apart form aesthetically! However, it was just too noisy, so it was traded in for a .22LR with a moderator firing subsonics. You have to get closer, but you make up for this with multiple shot opportunities. Wandering around the farm on a warm evening with a subsonic .22LR is about as fun as it gets...