There are certain weapons in the game that are able to benefit from more than one perk families. This article will hold the current multi-perk weapons, as well as reference those that historically had this trait but outperformed drastically and were modified. Pipe Bolt Action, when configured as Rifle, benefits both from Rifleman and Gunslinger Perks, enabling a specific niche where these weapons output extreme damage levels. The same thing applies to Pipe Revolver.
Interesting choice and the highest bare damage is achievable with Meat Hook, as it benefits from both Iron Fists (unarmed) and Gladiator (one-handed) melee perks. Pole Hook has also worked similarly, but with two-handed, but it has been changes ince.