A .223 will be a lot closer to the .357 than the .22lr. Like James said, maybe not a 30-'06, but the neighbors will know when you're shooting.
That said, the .223 (5.56) is a great varmint round. Very accurate and relatively flat shooting.
I'm glad that ammo availability isn't a concern for you.
It IS a concern for most of the rest of the country. There's not a single gun shop that I'm aware of, where I can walk in and buy .22lr. (even walmart hasn't had any on the shelves in months) Lots of other calibers are very limited in choice, if available at all. .223 is available, but mostly in FMJ.
If you have a reliable source for ammunition, I'd really like to hear about it.
The reason I state that it's not a concern, is not because of a secret stash buried in the mountains somewhere

but because I very rarely shoot and when I do, it's not all that much. I'm not one of those guys that likes to shoot 10 rounds as fast as possible, I take my time. When hunting, you pretty much get one shot.
As for 22lr, I didn't realize the shortage, but I have more rounds in my gun cabinet than I'll ever use, so I lucked out there. The reason I have so many is because my old Marlin 22 which hasn't been shot in forever, is about on it's way out and I don't even remotely enjoy shooting it anymore. A while back I bought a bunch of ammo and haven't used it.
So, I didn't mean anything secretive by my statement, I'm honestly just not concerned with it. Ammo will become available again, and the cost doesn't concern me for the same reason, i just don't use enough of it to matter. Sort of like a gas guzzling pickup truck, I don't care about fuel mileage because I doubt I put 1500 miles a year on.
Thanks for the comparison on the noise level. I don't 'think' noise is too much of a problem, but I guess I am slightly concerned about it so it's something to think about. I do have an old friend who has an AR and I'm sure he would let me shoot it, I haven't talked to him for a while but perhaps I'll touch base and drop a couple hints and see if he offers.
Edit: A 30 second google search shows that .223 seems to be readily available if you don't mind buying online. :confused3: