i agree with previous advices,
i can add that u are in a life moment of your gunners that is critical, as it is
the time for them to get experts and make vets.

try to reach 100-109-110 vets, i usually burn all the experts i get after battles,
when u reach 10-20 experts, make 1 or 2 tries for your gunners, and also for all the
other sailor.
when u reach 100-110 vets, stop making vets, and keep the experts as experts, to
try to bring them to full. it is not easy, it will take a lot of time and efforts.

the fastest way is as they adviced you, do AA. u will get experience, and will get the
maximum number of experts per battle as AA gives a bonus to experts conversion.
Also u got guns at this level which probably u will not see even where they land if u
fire at max angle, so keep em for those who are rushing, and help the front line bbs
to concentrate their fire on the scariest enemies instead of wasting their shots on
ships that u can kill urself.
u will get good spread only at lvl 80+, more tighter when u will reach the 90ies.
Boost is also a very good help, though it costs money and at max levels it normally
doesnt help anymore.but to reach those levels you need all the way through, so i
advice it.

good luck, hope to have been of any help.

That's what happen to who want to use big guns at lvl. Just lvl your gunner, about 10
above the required lvl or when you feel the spread is acceptable.

My advice is to use smaller ship like CA or CL if you are still in blitz. If you are 60+,
then AA in GB2, this can help you more than you can expect in gaining more expert, this
equals higher ability for the crew -> better. I think you should AA until BB2 or using BB1
with AA batteries. you can support your team with these set up more than fooling around
with sight range gun

The only way to get better accuracy is to:

1. Get more levels.
2. Get more experts.
3. Get more veterans.
4. Use a boost (not recommended)

They are level 65 for niv63 naval guns

u r forgetting a big factor.the accuracy ability of ur gunner.