Miles,
To put it mildly, I don't think Barnes has any clue about the effect of rotational velocity, based on their statement, "We have not seen any indication showing that jacketed bullets open wider because of rotational velocity."
There's been plenty of evidence of that. Anybody who's used a fast-twist .223 has seen it, but evidently Barnes has missed it.
Also, the point we were discussing wasn't whether increased rotational velocity would case monolithic bullets to open wider than they're designed to. Obviously, they can only open so much.
But there have been numerous instances where monos DIDN'T open fully, or at all, at longer ranges. Would increased spin have helped? I have no doubt it would, based on what other bullets do when spun faster.
