Possession of ammunition will send a convicted felon to prison for a mandatory 15-year sentence. Thirty-six-year-old Ronald Siebert entered a guilty plea in July. Video surveillance at a Cabela’s store showed Siebert and his girlfriend buying a gun and ammunition last year. Federal prosecutors say Siebert already had six felony convictions in his criminal history. He was classified as an armed career criminal, resulting in the mandatory prison time.