I have only done the 25 yard one time years ago and missed a nice buck. i don't know if it works for some ammo or not. it didn't with remington core locks back then. i always sight them in at least 100 yards. now i will leave them a inch or two at 100 cause i am shooting a long way in a clearcut now. if i only hunted 100 yards or less i would put it right on 100.