Re: reloading 1X fired brass
When I rebarreled both the 7 mag and 22-250, I reused all the brass from the factory chambers. The only issue I ran into was if the case had, had enough reloadings on it to have hardened the shoulder some, it would chamber hard, but annealing fixed that. NO I think your process of full length sizing is fine, but annealing seems to alleviate some issues.
Keep in mind the animals we shoot for food and display are not bullet proof. Contrary to popular belief, they bleed and die just like they did a hundred years ago. Being competent with a given rifle is far more important than impressive ballistics and poor shootability. High velocity misses never put a steak in the freezer.