1991 was the last year I personnally used the hornaday interlock for big game, shot a moose three times with this bullet, out of a 7mag @100yds all but one fragmented to nothing and it weighed 70gr down from a start weight of 175gr. Started using the X bullet after that with very good success. Hornadays have there place, but big moose reqiure a larger cup/core bullet than the 7 at a slower velocity. So maybe it was wrong application.......