I've NEVER experienced cracked case necks on the initial firing, but lately I've heard of it happening to several shooters. Your .004" measurement is a sign that your rifle is OK. I always inspect my brass very carefully, and I reload a lot of Winchester brass. I've found it much more uniform than Remington brass.
I've reloaded more than a dozen different rifle calibers (since 1965), and I've only had the necks crack with one caliber. It was the 22-250 Remington. It happened about 30 years ago, and it was also with Winchester brass. However, it only happened after the cases were reloaded several times.