The M193 ball round is a bit too solid for small animals. Something like the Vmax in 40 grain, or the NTX in 35 grain makes a GREAT ground squirrel load! Loaded in the 5.56 case you're looking at 3,500 fps easy which means absolute EXPLOSION on impact! Just the other day I shot a coyote with my Fiveseven 5.7x28 stoked with Barnes 36 grain Varmint Grenades and the animal dropped where he was hit with a single shot just behind the foreleg! This load was ONLY traveling around 2,000 fps on impact so any ".224" bullet going almost double the speed is just obscenely destructive!