Just curious, but why would anybody want to shoot "500 rounds of .22" in a weekend? On a typical range outing, I might shoot 50 rounds of .22, .38, maybe 25 rounds of .357, and up to 100 of 9mm. That's usually enough to check my accuracy, handling, and reliability.
Oh, sure, I know that for some guys, it's a counting contest. "I shoot 10,000 rounds of 223 every day, all day, 365, 24/7. I shoot 100 million rounds a week and if you don't, you're a sheep-person anti gun-grabber!"
Yeah, I get that, but it really seems crazy to me. Regular, consistent, focused training should not require thousands and thousands of rounds to get to where you need to be.
I'll go further: If you need to shoot a quarter million rounds a year of .22, then something is probably wrong with your understanding of firearms. Your kinesthetic memory, handing, sight picture, breath control, trigger control, aim, heart rate, and attitude are all under your control.
Simply firing more rounds will not make you more proficient if you can't handle the above variables.
Hearkening back to the "In the good ol' days" thread that got locked earlier, old-timers can tell you stories about buying a string of 5 or 10 .22s at the 5 and dime store, and going out and making those precious rounds count.
Our - drum roll, please - Founding Fathers had to shoot complicated flint-lock rifles with wads and loose gunpowder and home-cast ball shot, and I doubt they won the Revolutionary War by throwing a quarter million rounds downrange every other day.
In short, if you're wasting that much copper and lead and cordite, you might want to check your training methodology and figure out what it is you're trying to accomplish.
Don't get me wrong: It is your right and it is your freedom and your liberty to shoot 100 quadrillion bazillion rounds of .50 caliber ammo every second of every day. You are allowed. But do you understand why some people might be laughing at your lack of expertise?