The Model 512 was made from 1939 to 1962. There were about 395,000 made, including a version with a peep sight. They are about the only under-barrel tubular magazine .22 that really seems to work without giving a lot of trouble. The magazine holds 22 Short or 15 Long rifle cartridges. Post 1950 rifles are grooved for a telescope sight.
The 512 was part of a long-running series of relatively inexpensive but high quality rifles. The 510 was a single shot, the 511 a box magazine repeater, and the 513 a low cost target rifle. Thousands of the latter were bought by the armed forces for rifle team use and training.
The 512 is still one of the best youth rifles on the market.
Jim