I have used many replacement style fixed blades ... a few years back i tried the mechanical s. had a broad side shot on a doe at 10 yards and arrow deflected on a rib causing the arrow to pass through just under the spine. Just found some hair. No blood .I looked for 2 hours that night and called off work the next day to search in the pouring rain.Never found anything but hair and 4 days later i found her with the arrow still in her spoiled and half eaten by the yotes.Because I couldnt get a new bow to shoot my fixed blades I took the easy way out killed an animal with no recoveryand missed 8 hours pay ... made me sick.The mechanicals i was shooting were acurate. It was the angle of the shot... had that shot been made with a full cut on point or trocar point there is no doubt in my mind that deer whould have been in the freezer.Smashed all the mechancals i had , tossed them in the trash and put the bow in the closet for the season.I have since fixed the problem and back to shooting muzzy 4 blade, and have had many clean kills since.Dont jump on me im not slamming anybody for what they use its just my expierience... couldnt stand the thought of a buck of a life time rotting away in a thicket someplace.