I've never doubted expansion begins immediately upon hitting an animal with most bullets. what I do wonder about is the differences in reaction on a plastic tip thin jacketed bullet with a hollow point when it hit's a tiny twig or a few Blades of grass BEFORE hitting the animal.
Of course there wouldn't be any difference in the quality probably of a plastic tip between a ballistic tip an accubond or a TTSX.... but I do think there are huge differences in the depth and width and makeup of the hollow point itself. somehow I think a lead filled hollow point...ie cup n core ....could be much better than air filled hollow point under a plastic tip.
And quite possibly the good old round nose bullet of 25 years ago could be better than all of them...hitting tiny amounts of trash on its way to the animal.
I guess the easiest way to summarize what I'm trying to say is if a worker at the Nosler Factory was installing tips incorrectly on bullets and it turned them into fragile blow up on impact projectiles couldn't a piece of twig or grass do the same thing?
IMO you are overthinking the bullet capability. Hitting a twig, grass, or whatever would most likely deflect the bullet in some degree.
My suggestion is: make a clean shot without hitting anything. Placement is more important than comparing bullet to bullet. Just about any 160gr bullet will be a clean kill with a proper placement.
If you cant take a clean shot, DONT SHOOT!
