Fentanyl makes a much larger impact. There were around 14,000 non-suicide firearm deaths in 2018, the most recent year with stats. Fentanyl killed around 110,000 in 2022.
Both issues disproportionately affect small segments of the population though, rather than being general hazards. Driving deaths for example tend to be more evenly distributed.
https://en.m.wikipedia.org/wiki/Gun_violence_in_the_United_S...
https://www.npr.org/2023/05/18/1176830906/overdose-death-202...