Youth who acquire a juvenile crime record may be at increased risk of perpetrating gun violence as adults. North Carolina and 22 other states permit young adults who were adjudicated by a juvenile court - even for some felony-equivalent offenses - to legally access firearms. Effectiveness of gun restrictions for adults with juvenile crime histories has not been systematically studied. This article reports findings from a longitudinal study of arrests and convictions for gun-involved and other offenses in 51,059 young adults in North Carolina, comparing those with gun-disqualifying and not-disqualifying juvenile records. The annualized rate of arrest for gun-involved crime in those with a felony-level juvenile record was 9 times higher than the rate of reported comparable offenses in the same age group in the North Carolina general population (3349 vs. 376 per 100,000). Among those with a felony-equivalent juvenile delinquency adjudication who became legally eligible to possess firearms at age 18, 61.8% were later arrested for any criminal offense, 14.3% for a firearm-involved offense. Crimes with guns were most likely to occur among young adults who had committed more serious (felony or equivalent) offenses before age 18; had been adjudicated at younger ages; acquired a felony conviction as a youth; and spent time in prison. The prevalence of arrests for crimes involving guns among young adults in North Carolina with a gun-disqualifying felony record acquired before age 18 suggests that the federal gun prohibitor conferred by a felony record is not highly effective as currently implemented in this population. From a risk-based perspective, these restrictions appear to be justified; better implementation and enforcement may improve their effectiveness. Gun crime prevention policies and interventions should focus on these populations and on limiting illegal access to firearms.