I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear about your situation.
Under federal law, possession of ammunition by someone who has been convicted of a felony is punishable by up to 10 years of imprisonment (and fines). 18 U.S.C. 922. That means you're entitled to have a lawyer appointed for you at no expense if charged with a federal crime and you can't afford one. If you're willing to plead guilty, your lawyer may be able to help you reduce jail time. A small amount purchased as a gift could help you argue for a lesser sentence than if you had made a large purchase for personal use.
The related California statute is a misdemeanor, punishable by up to one year of imprisonment (and fines). Cal. Pen. Code, Section 30305. Unless you're found with the ammunition on federal property such as a military base or a national park, odds are that you'd be charged with a state crime rather than a federal offense, especially if your prior convictions are under state law.
The bigger issue is that one of the conditions of your parole is that you follow all the laws, and parole CAN be revoked if you're charged with a crime, even if you're not convicted. The standard of proof is lower in a parole violation hearing than in a criminal court. The judge has discretion to add additional terms to your parole or only make you go back a short time, but he can also make you serve the entire rest of your sentence. Talk to your lawyer, if you had one in the underlying case (or call the public defender's office if someone was appointed). Your lawyer can talk to your parole officer and see if there's any way to try to avoid that scenario.
If you have any questions or concerns about my response, please reply WITHOUT RATING. It's important that you are 100% satisfied with my courtesy and professionalism. Otherwise, please rate my service positively so I am paid for the time I spend answering questions. If you are on a mobile device, you may need to scroll to the right. There is no charge for follow-up questions. Thank you.