When "real world field testing" includes accepted methods of BC determination (near and far velocity or near velocity and time of flight combined with measured environmental conditions ie: Kestrel), then I am in agreement.
However, when "real world field testing" amounts to pseudo science of "confirming" theoretical BCs from long range drops and not bothering to record the actual environmental conditions (temp, pressure, and humidity), then I am doubtful. We've seen a lot of copper and brass bullets fail to demonstrate measured BCs that were expected/predicted from their lengths and form factors. A lot of Nosler's numbers are inaccurate, and the BCs published by Barnes have gotten much more accurate (and lower) since they have actually been measuring their BCs on their 300 yard range.
Even Berger has gone through several rounds of adjusting their published BCs downward to better fit repeatable experimental measurements. They went through a first round of downward adjustments after Litz joined them, and then they even needed to adjust a .338 BC downward after independent testing failed to confirm an early experimental BC that was determined by Litz.
BCs that are really this high are an extraordinary claim that should require extraordinary validation, including independent testing. We'll be happy to schedule BC testing of .308 bullets if someone sends them to us, but at price of buying these bullets off the shelf, we're no longer eager to spend our own money testing every new claim of extraordinary BCs. We've spent thousands of dollars testing these claims in the past, and we've been underwhelmed.
