User blog comment:Shinhwalee/Major Event Preparation Guide for Admirals/@comment-26192265-20150714055049/@comment-749631-20150715213402

According to http://jbbs.shitaraba.net/bbs/read.cgi/netgame/13745/1400461230/878, it have been hypothesized that for 14cm or 15.2cm gun series, bonus value = 2×√(no. of Twin Gun Mount) + √(No. of Single Gun Mount).