Company comp vest sizing

I'm thinking of buying a company pro vest, I currently have an A10 but it's getting old.
I've a 40" chest but wear a large A10, I would normally wear medium.
Can anyone tell me is the company vest a tight fit like the A10 or should I order a medium (true fit)

***before anyone suggests trying it on, there are no Company reps in my country andI have to but it online form the U.S.***

Thank you