So i am planning on making a new character focused on handguns ( the cowboy type) and need some help with a few things i plan on getting the highest crit chance i can ( without wearing boone's beret cause i hate it). i plan on using Lucky for the majority of this playthrough which has a 2.5 multiplier. for this build though i have a question about that

does the trait built to destroy or any crit chance perks receive the 2.5 multiplier or is it a flat bonus?

so any suggestions for this build would be highly appreciated

Built to Destroy and perks that increase critical chance (except for Ninja, but that one only affects melee and unarmed weapons) add only to your base critical chance. The weapon's critical chance multiplier is not affected.