Does silencer attachment reduce dmg in Warzone?

^ topic

No, it just stops you from appearing on the motion sensor when firing, but not when you are moving.

Does it decrease range?

No the silencer only stops you from appearing on the radar when firing. Perfect for players who want to go all splinter cell on the other team.

My testing of 90% of the attachments/variants using an AR

No. The only draw back from using the silencer is that your spread fans out sooner. Halo dmg model is very simple: It’s all about the spread and recoil, and for some precision weapons shot placement. There is no minimum/maximum dmg and no range really. “Range” only applies to the distance at which your reticle turns red so aim assist locks on.