Introduced in 1933, the Model 63 was the first semiauto rifle offered by Winchester chambered for the standard .22 Long Rifle cartridge. It had the square receiver that was a trademark of all early Winchester semiautomatic rifles.

In the military arena, the new bolt-action, repeating rifles firing the recently developed small-bore, smokeless-powder cartridges were all the rage. Even more radical was the number of designers working on semiautomatic and fully automatic firearms.

In 1891, Winchester began an R&D program to develop a semiautomatic sporting rifle. For more than a decade, company engineers William Mason and Thomas C. Johnson examined various operating systems.

Johnson developed an operating system in which a relatively light bolt was attached to a counterweight that balanced it during recoil. Later termed a "blowback" operating system, when a cartridge was fired, the rearward forces of the powder gas had to first overcome the inertia of the bolt, counterweight, and recoil spring, which kept the action closed until pressures had dropped to the point where it was safe to extract the spent cartridge case. It was simple in theory, but the tough part was calculating the amount of force needed to reliably cycle the action.

Johnson located the counterweight under the barrel where it reciprocated inside the hollow wooden forearm. As the bolt reached the limit of its rearward travel, it impacted against a spring-loaded buffer in the buttstock that prevented undue stress to the receiver and also provided forward impetus to the bolt, thereby ensuring proper functioning.

Winchester introduced Johnson's design as the Model 1903 Self-Loading Rifle, and it was the first commercially manufactured semiauto- matic rifle. It was chambered for a then-new, proprietary, smokeless-powder, rimfire cartridge called the .22 Winchester Automatic. At that time, most companies were still loading the .22 Long Rifle cartridge with blackpowder and/or semismokeless powder, the residue of which made their use in semiautomatic firearms impractical. For this reason, Winchester designed the Model 1903 so that it could only be fired with the .22 Winchester Automatic cartridge.

The Model 1903 was an immediate success, so much so that it encouraged Winchester to introduce a centerfire version--the Model 1905 Self-Loading Rifle. By 1910, most American ammunition companies were offering the .22 LR loaded with smokeless propellant, and in addition to being significantly cheaper, that led to the cartridge being more widely distributed than the .22 Winchester Automatic.

In 1924, Remington executed a marketing coup with the introduction of the Browning-designed Model 24 semiauto rifle chambered for the .22 LR. The folks at Winchester realized that they needed to play catch up. Unfortunately, things did not work out very quickly in that effort, and it wasn't until 1933 that the basic design was modified to handle the .22 LR cartridge and released on the market as the Model 63 Self-Loading Rifle.

The Model 63 featured an exposed, square receiver that was a common feature of the Winchester Model 1903, 1905, 1907, and 1910 semiauto rifles, and it came with an uncheckered, walnut forearm and pistol-grip buttstock. Early-production rifles had a 20-inch round barrel, but the following year, the option of a 23-inch barrel was introduced. The latter became so popular that the shorter tube was discontinued in 1936.

A 10-round, tubular magazine located in the buttstock was loaded by rotating the magazine end cap--located in a cutout in the buttplate--and withdrawing the inner magazine tube until it stopped. Rounds were then inserted nose-first into the magazine through a teardrop-shaped opening in the right side of the buttstock. Pushing the inner tube back into the buttstock compressed a spring-loaded follower, applied pressure to the cartridges, and fed them into the receiver where the bolt picked them up. Another feature common to the earlier Winchester semiauto rifles was that to chamber a round, one pressed on the knurled end of a rod--called the operating sleeve--that extended from the front of the forearm; this retracted the bolt to charge the rifle or extract an unfired cartridge. Pressing in the operating sleeve and rotating it 90 degrees locked the bolt in the open position.