Here is my experience using a .17HMR the first time I ever went moonlight calling several yrs ago.. keep in mind I have this gun zero'd at 100yds with very small groups. On this outing I was using the 20gr hollowpoint. First sit, didnt call for a minute and had two yotes come running in on a sprint. They both stopped at 50 yards or less in a wide open field and i was using shooting sticks. Pulled the trigger and watchex him run across the field for several hundred yards before disappearing into the night and over a hill. The snow was hard from a melt and freeze so I couldnt track him and the bullet hole was too small for blold.. never found him. we went to another spot, called one into 30 yards. Put it behind the shoulder and squeezed the trigger and the yote took off. Bolted another round in and shot him on the run at 50 yards and dropped in his tracks. When we went to get him he was laying there still and we went to ck for blood for the heck of it in the first spot ibshot. We looked over and the yote jumped up and ran off! Never found him either. Went to some other spots and didnt see any and then the last spot we went, two came running in to about 50 yds or so and same thing, shot and they ran off... thats the last time iver used that for yotes. I dont know if it would work better to shoot them in the head or not. I think maybe if it was a fresh snow we could track in then we would have found them. I have no doubts thatvthey died but they are a tough animal to kill. I now have a .204, .22-250 and .223