The Remington rolling block rifle models No. 1 through No. 5 are all similar but with different size actions to accommodate various calibers. The No. 6 was the economy version of the rolling block action. It appeared later with a longer, thinner, less contoured and slab-sided receiver. The patent date for the No. 6 was July 22, 1902. No. 6 rifles were chambered for various rimfire cartridges up to at least .32 caliber, but it is most commonly seen as a .22 rimfire. Being a single shot with a .22 Long Rifle chamber, my personal No. 6 can handle .22 BB, .22 CB, .22 Short, .22 Long and .22 LR cartridges interchangeably.