[dredmorbius]

If you're referring to the United States, the answer is that yes, weapons manufacturers were being held liable for firearms-based violence, until passage of the "Protection of Lawful Commerce in Arms Act" of 2005:

<https://en.wikipedia.org/wiki/Protection_of_Lawful_Commerce_...>

(Note that the bill passed with significant Republican and Democratic support.)

Which is to say, conventional notions of contributory negligence and liability existed until sufficient political power was accrued by the arms industry to write itself out of same. The cited Wikipedia article names several such suits, notably by the cities of Chicago, IL, and Bridgeport, CT.