The earliest you can possible cap reload with UK armament sailors is;
Base 13, Boosted, 210 vets, 330 experts and that would require lvl 85.
If you can get your hands on 2 Hero sailors... you can drop it to 210/320 at lvl 82.
I'm going through the same with a pair of UK AA gunners of my own, but they're part of a CV crew that doesn't even have any T slots between lvl 50 and 73. But once I do get to 73, I think I'll be content having them use HH until theyre reload capped.