how do i know what weapon class a weapon is?

[Pipsqueek]

does it help getting trophies?

[Faeb]

you can see the weapon class when you hover over the ammo in your inventory or buymenu.

[PixelDonut]

https://steamcommunity.com/sharedfiles/filedetails/?id=1266155889

[Pig Mac]

The ammo tells what class it is if you hover over it. But at the same time the integrity rating is a bit different.

I haven't found any updated Integrity chart, after the weapon Pack 2 release, but this one at least gave an overview https://docs.google.com/spreadsheets/d/1NjzGrdT3XqzoOTbTg4u3PgTILjIjjrEWYI8j3_jfmKM/edit#gid=1585983930

Oops.. too late ;)
Thanks DigitalCapone

[GhostyGG]

yeah the ammo will tell you since a lot of the guns have different ammo types.