The "shortest" reload times are 60% under the guns' displayed reload times. That happens if your gunners have hit the reload cap (and that may be different, apparently between 2.6 and 2.7 M true ability).

Just the ordinary gun data, if you were trying to find them, are in "Game Info" -> "Components"

And two different nations' guns with identical stock reload times would have identical reload times with capped gunners on, if that's what you're asking (well, there might be an ever so slight difference in capped reload times if one gun is an AA gun and the other a normal gun).

To expand on Erics post.

Unboosted gunners need 2,040,000 TA to reach their reload cap of -55%

Boosted gunners need 2,400,000 TA to cap, but can reduce reload time by -60%

Excellent, thanks, Benser.

I know that the "old" reload cap was already at 2.4 M TA (giving 50% reduction in rld time) - so it basically stayed the same for boosted gunners and giving more of a reduction of 60%?