"Rubber bullets" is a bit misleading. These cartridges are "less‑lethal munitions"

The LA police are most likely used foam/sponge rounds. Wile it likely to to inflict pain without penetration, but they can still seriously injure.

37 mm launchers seem to be used to "pepper" a crowd

But I'm seeing the LA police using the twice as heavy 40 mm launchers (single-shot) deliver heavier sponge rounds with more impact. It's supposed to be used at longer range, but seemed to be used a very close ranges in LA.

At the ongoing Los Angeles protests, law enforcement is most likely using:

While designed to minimize injury, they carry real risk of serious harm if fired too close or to sensitive areas, which is definitely what I'm seeing in videos.