Depends on the range, but yes. Get a ballistics calculator like ChairGun and look at the downrange energy at various ranges. Heavier pellets deliver more energy downrange. I've read that it only takes about 3 fpe for a humane kill on a squirrel, or about 5 fpe on a rabbit.
107 yds., rabbit, .25 Marauder in stock trim. One heart / lung shot. Just keeled over and didn't even twitch.
I'm more proud of a single 73 yd shot I just got on a ground squirrel in gusty 10 mph 90 degree crosswind. First time I have ever even dealt with a cross wind! Sometimes it's better to be lucky than good! LOL!