There's absolutely no doubt that the .22 Long Rifle cartridge is the longest surviving version that's still with us. Even though there may be a messily few pitiful souls, who try to argue against just about everything posted in these forums, they can't argue that some success has arrived from the variations of the steadfast .22 Long Rifle round. I have quite a few of the .22 Winchester WRF and .22 Remington Special rounds that are interchangeable between those makers pump action, tube fed rifles, but, the .22 Long Rifle cartridge won that battle quite a while ago. Here are the currently produced .17 and .22 rimfire cartridges still being produced, the 5 MM Remington has periodic production, but they are still available: It was posted that the .17 Aguilla and High Standard are the same cartridge. Well sorta. They have the same shape case, but the bullet involved with the .17 Aguilla has a long tapered ogive and needs to jump almost 1/8 inch to engage the rifling. They work, but are not as accurate. As a side note: ALL of the .17 Mach 2 ammunition is made by Hornady, they just use different colored polymer tips for each various brand selling this round.