From what I understand, which is little, The MBF bullet feed die uses the weight of the bullets in the column to sort of seat the bullet in the case. The Hornady one is just the weight of the one single bullet. Ive used both and no matter what I tried the Hornady one was inconsistent. I tried making the collet bigger, smaller, more force, less for, nothing worked 100%. The MBF die is perfect.