lets first understand why escort AA boat is favoured with fast reload guns.

well, escort aims bad, that's why you need fast reload to counter that.
what's the point of having escort AA ship, which will miraculously start to engage at 25 angle, hitting your own team planes (both IJN and MN have such long range guns, though they deal very small dammage to the planes) and then stop AAing while having planes over him, due to gun's limited max angle... ?

so you want guns with fast reload and high max angle.

but words are words, best is to figure it out yourself what you need. So try some different nations AA platforms with different gun setups as escorts.

The problem is that escorts shoot where the boat or plane is at, not where it will be when the shells arrrive.  Most escort AA ships are just plain lucky to shoot anything, most likely they'll hit your own team's fighters before they shoot an enemy plane down.   A squadron of TBs or DBs are not deterred by an escort in the slightest.

Best use of an escort is to identify subs.

Thanks for the replies. I have noticed what Ultra_Dog commented on about being lucky to hit enemy aircraft even hitting friendly before your oppent. I as a CV player am not deterred by much when I encounter an AA escort although I have noticed it causes me to take care on my approach which buys my target a second or two. Those few moments can make a huge difference in some situations which is what I am aiming for. Im not under the impression I can build a cure all  AA escort for deterring enemy planes. What I want is something that packs a punch, is the most likely to hit its target, and provide sight against SS. Im really starting to lean towards an UK machinegun boat and going to do more research before I start this crew and grind this coming weekend. 

Well thought I would give an update. In the last few days I have been very foturnate with the sale of severeal Elite BVE sailors and came into a very nice stack of credits. On top of that I had the luck of catching someone selling lvl 107 bve US ACC gunners and lvl 64 bve RLD gunners for half there value. The 107 gunners I believe are reload capped and im using them for AA while lvling a BO and the rld gunenrs. Havent decided whether I want to lvl support sailors at this time and also have the opportunity for a BB as the stats of these sailors were 10/10 on acc sailors and 11/11 on the reload. I got them for so cheap I just couldnt pass it up and have what I was wanting without the hastle of grinding an elite crew. With all of that said I know US isnt the best AA wise amongst the community but it gets the job done for skilled AA players which I consider myself one. I have alot of experience taught by some of the more hardcore EU players from back in the day and played alot with IJN DP gunners on BB project for a good year. Its not the best it gets the job done when I play with the crew have yet to test it as an AA escort. Still might grind a UK crew for the escort and use the machine guns which from I hear is the most affective. 

Auto AA Escort... None are effective.

They only hit if enemy planes fly circles in your range. A decent CV/BB scout won't do that.

I agree with UDog. BB better to use Escort ship to help detecting SS, load it with normal gun to pop them as they surface. CV can use that setup too, freeing T slots for other sailors.