User blog comment:Friguceler/Digging around for Fit Guns system and stuff/@comment-26948048-20160305184354

I'll note that there is no overweight penalty on CLs whatsoever; only a fit bonus. Equipping a 20.3cm will not incur any negative modifiers, but equipping a 15.2cm and lower calibers will provide a hidden accuracy boost.

There are several other assumptions that have since been proven incorrect according to recent test data; see this image for a table of large-caliber guns and their respective accuracy modifiers on several classes.