You really have to look closely for an import marking, as some are really tiny. Maybe on the bottom of the barrel, maybe on the receiver below the wood line.

You might want to get a technical inspection by a gunsmith. We loaned many carbines to the Koreans, who used them hard. When the spare parts ran out, the Korean Army armorers made some repairs that our armorers would not do, such as weld a broken bolt lug.

Neal