Wineman that was what supposedly made the M16icon so deadly the bullet tumbled and IF it hit you you never knew where it would exit as it tumbled through the body but they also found that they couldn't hit anything with a precision shot if they needed to so they changed it to 1 in 9 and now it's accurate but you lost the devastating tumble effect so now you have a .22 battle round. the Russians solved that problem with the 5.45x39 it's a FMJ but the tip under the jacket is hollow so it flies great and when it hits the tip bends and then it tumbles.