I have been promoting the use of WFN bullets on a 1911 forum whenever the ball vs hollowpoint subject comes up. It is like beating my head against a brick wall. I have used the Permanent Wound Channel Formula to give examples of what a .45 cal bullet with a 0.36 inch meplat could do based on the formula. The validity of the formula is challenged as it is hard for the hp contingent to visualize a larger than caliber wound from a non expanding bullet. Are the wound diameters predicted by the formula validated by actual results in game animals? Do they correlate to testing in gel? Very few ammo makers use WFN bullets for semiauto ammo so there isn't much data on their use. Double Tap is the only one I know of using a 200gr WFN with a 0.32 inch meplat in the 40 S&W and 10mm. The formula predicts a 0.80 inch wound channel and the result is viewed with mass skepticism. I guess the bottom line is, can one predict with any accuracy what the wound size will be in tissue using this formula?