Legal Question in Criminal Law in California

Possession of live ammunition is not a crime by itself. There has to be some other factor that makes possession of the live ammunition a crime, such as possession by a felon, or having it on a plane or in a school, etc. You don't provide any information as to that issue.

Possession of brass knuckles is forbidden by Penal Code section 12020. That section is a "wobbler" which means it can be charged as either a misdemeanor or a felony, depending on the facts of the case, and your criminal history.

If convicted as a misdemeanor, you face informal (otherwise known as "summary") probation, up to one year in a county jail, and a maximum $1,000 fine.

If convicted as a felony, you face formal probation, up to one year county jail (if probation is granted) OR (if probation is denied) up to 16 months or two or three years in the California State Prison, and a maximum $10,000 fine.

In addition, the brass knuckles are usually confiscated and not returned unless you have some special legal defense.