your catching on! some rifles like some bullets jammed, some don't, a lot like some jump, having some jump is not a bad thing, when you have peak pressure before the bullet gets past the throat is hard on brass, and shoots slower and accuracy will probably be no better unless you have a custom chamber
this group was fired with a 140 gr. Berger, 30 thou. off the lands at a lazered 752 yards

RR