The "significant gain" is about the same as another inch or two of barrel length. In other words, a 22" 30-06 AI should be similar to a 24" 30-06. This can also be read as "not enough to matter".
I will not be pushing a 24 inch 30-06 anywhere close to 2985 fps with a 180, now would I run it to 2758 with a 200. Yet both loads are listed in the Nosler manual.
The caveat is, they used a 24 inch tube to do it. If I still thought I needed a 30 cal, it would be wearing 26 inches and we could add 40 fps to those numbers.
