Pretty quiet. - CCI Ammunition Quiet-22 .22LR 40 Grain Lead Round Nose Rimfire Ammunition

They're not as quiet as Aguila Colibri or Super Colibri, of course, but they're cheaper, they're more powerful and at least they're available. When I shoot them through my 10/22 they don't cycle, but when I shoot them through my Winchester Wildcat they generally do cycle. And when suppressed, they're almost silent. I've got the Aguila on backorder here on Optics Planet, but until they're available again, CCI Quiet are my go-to plinkers. They are quieter than other Quiet or Suppressor Ready rounds. As I recall, the LRs aren't as quiet as the CCI CB Shorts, though. You can get an idea of how much powder is in these rounds by knowing the bullet weight and velocity. 40 grain at 710fps requires more pop than 29 grain at 710fps.