Soviet-era SSh-40 or SSh-60 Steel Helmet unissued

This is not a U.S. military helmet. It is a Soviet-era SSh-40 or SSh-60 Steel Helmet, or a very similar clone produced by a Warsaw Pact nation (like Poland or Czechoslovakia) or China during the Cold War.

Here is a breakdown of the key features from your photos:

• The Red Star: This is the most significant identifier. The red star is the classic symbol of the Red Army of the Soviet Union and was the primary national insignia for their military forces. U.S. military helmets have never used this marking.
• Helmet Shape: The distinct "pot" shape is characteristic of the Soviet SSh (стальной шлем, or steel helmet) series. It is different from the American M1 "steel pot," which consists of a separate steel shell and a liner. This helmet appears to be a single shell with the liner directly attached.
• Liner System: The photos of the interior show a webbed suspension system with a leather or faux-leather band, which is consistent with the liners used in these Soviet-bloc helmets.
• Retail Sticker: The white sticker with the barcode and the English text "SER STEEL POT HELMET W/ HA" is not a military marking. This is a modern inventory or price sticker from a surplus store or importer. This indicates the helmet was likely sold as military surplus.
• Condition: The helmet appears to be in excellent, possibly unissued, condition, often referred to as "New Old Stock" (NOS), given that it is still in a plastic bag.