Manufactured in 1878. The barrel is stamped with the one-line Hartford address. The ejector rod has the correct bullseye head. The caliber marking "45 CAL" is stamped on the left side of the trigger guard. The frame has the three-line, three patent dates marking on the left side. A Colt factory inspector letter "B" is stamped in the hammer well. Matching serial numbers are stamped on the frame, trigger guard, back strap, cylinder ("4315") and barrel ("4315"). The loading gate is marked with the assembly number "378". Blade front and frame notch rear sights, blue finished barrel, cylinder and grip straps, casehardened frame and hammer, and fitted with a smooth one-piece walnut grip.