8/14/20 - This is a nice Underwood M1 Carbine with rare and desirable 'B' code receiver, indicating manufacture by Singer. From serial numbers 2,630,000-2,655,000 the B code is reported and this one falls in that range. A full parts guide is included in the photos of the listing. The finish on the rifle is excellent with minimal rub wear. Excellent bore. Stock is in terrific condition and without defect. It has faint cartouche on the right side, and a 'U' marking on left which may be an arsenal stamp. Excellent bore and good mechanics.