the speed it shoots accurate at .. my main concern is random predators after muy chickens including squirrels, yes they chase the hens trying to lay out of the coop when they 'take over' the food .. my yard is about 100yX75 plus the surrounding30-40y comes into play occasionally and 'every' shot is different usually, all different ranges .. speed doesnt matter, the only concern is hitting and taking out what your after .. slugs dont matter, enrgy transfer doesnt matter , etc etc ..its all shot placement and ability to hit things in varying conditions - up, down, sideways, through cover, moving ... you need to know how your gun shoots in every corner and situation .. jcking off adjustments and different pellets all the time doesnt lend itself to grabbing the gun and nailing something offhand real fast .. pick what works good and you can use every time and adjust your gun accordingly and keep it there .. the rest is learning the shots and angles ..