California's Proposition 65

WARNING: Use of lead-based ammunition in a firearm may result in exposure to lead residue, a substance known to the state of California to cause cancer, birth defects or other reproductive harm. Reasonable protective measures should be used to avoid or minimize exposure in use or cleaning. After use or cleaning, users’ hands and face should always be thoroughly washed before consuming any food or drink. 

For more information : www.P65Warnings.ca.gov