Just the other day dad brought out his old Winchester in 5mm Magnum. These things were made in the 1960's, but the caliber never caught on and it all but died out. Dad bought a few of the rifles when the ammo was impossible to find and stuck them on the wall. Now the 5mm ammunition is being made by a few companies, and he's got enough accumulated to feel comfortable shooting some of it up. It's a rimfire round, but you can tell it's hitting a little faster than .22 Magnum (dad's first love) even at such close range. Recoil is still nil . . . . it's a nifty little round. I can see why it was designed, but I can also see how .22 Magnum killed it off the first time. My guess is that without the internet, no one company would be able to make enough money on this caliber to justify producing it today, but happily, customers can find the stuff from across the country nowadays, so the relatively few people buying it can be exploited by one or two companies. Welcome to the future, where your dead old calibers are resurrected as terrifying rimfire zombies.
Today dad took his trap thrower out to the pond, and when his mowing was done, he taught Kane to shoot clay pigeons with a sweet little Stevens .410 SxS that's just about his size. He also stopped in at the local Military Surplus/Shrine to John Wayne (just look for the place with the 8-foot-long M16 on top of the sign) called "Birds and Brooks" to get more plinking ammunition. This time he came away with .32 Long for his MAS 1935 and 7x57mm for his funky little cut-down Mauser 1893 carbine.
And that's why grandpa's house is more fun than home, kids. ;)